Sr Examen

Otras calculadoras

f*(x)=4*x^2-2 la ecuación

El profesor se sorprenderá mucho al ver tu solución correcta😉

v

Solución numérica:

Buscar la solución numérica en el intervalo [, ]

Solución

Ha introducido [src]
         2    
f*x = 4*x  - 2
$$f x = 4 x^{2} - 2$$
Solución detallada
Transportemos el miembro derecho de la ecuación al
miembro izquierdo de la ecuación con el signo negativo.

La ecuación se convierte de
$$f x = 4 x^{2} - 2$$
en
$$f x + \left(2 - 4 x^{2}\right) = 0$$
Es la ecuación de la forma
a*x^2 + b*x + c = 0

La ecuación cuadrática puede ser resuelta
con la ayuda del discriminante.
Las raíces de la ecuación cuadrática:
$$x_{1} = \frac{\sqrt{D} - b}{2 a}$$
$$x_{2} = \frac{- \sqrt{D} - b}{2 a}$$
donde D = b^2 - 4*a*c es el discriminante.
Como
$$a = -4$$
$$b = f$$
$$c = 2$$
, entonces
D = b^2 - 4 * a * c = 

(f)^2 - 4 * (-4) * (2) = 32 + f^2

La ecuación tiene dos raíces.
x1 = (-b + sqrt(D)) / (2*a)

x2 = (-b - sqrt(D)) / (2*a)

o
$$x_{1} = \frac{f}{8} - \frac{\sqrt{f^{2} + 32}}{8}$$
$$x_{2} = \frac{f}{8} + \frac{\sqrt{f^{2} + 32}}{8}$$
Teorema de Cardano-Vieta
reescribamos la ecuación
$$f x = 4 x^{2} - 2$$
de
$$a x^{2} + b x + c = 0$$
como ecuación cuadrática reducida
$$x^{2} + \frac{b x}{a} + \frac{c}{a} = 0$$
$$- \frac{f x}{4} + x^{2} - \frac{1}{2} = 0$$
$$p x + q + x^{2} = 0$$
donde
$$p = \frac{b}{a}$$
$$p = - \frac{f}{4}$$
$$q = \frac{c}{a}$$
$$q = - \frac{1}{2}$$
Fórmulas de Cardano-Vieta
$$x_{1} + x_{2} = - p$$
$$x_{1} x_{2} = q$$
$$x_{1} + x_{2} = \frac{f}{4}$$
$$x_{1} x_{2} = - \frac{1}{2}$$
Gráfica
Respuesta rápida [src]
               /            ___________________________________________                                                \       ___________________________________________                                                
               |           /                       2                       /     /                      2        2   \\|      /                       2                       /     /                      2        2   \\
               |        4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/||   4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/|
               |        \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *sin|------------------------------------------||   \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *cos|------------------------------------------|
     re(f)     |im(f)                                                      \                    2                     /|                                                      \                    2                     /
x1 = ----- + I*|----- - -----------------------------------------------------------------------------------------------| - -----------------------------------------------------------------------------------------------
       8       \  8                                                    8                                               /                                                  8                                               
$$x_{1} = i \left(- \frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{im}{\left(f\right)}}{8}\right) - \frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \cos{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{re}{\left(f\right)}}{8}$$
               /            ___________________________________________                                                \       ___________________________________________                                                
               |           /                       2                       /     /                      2        2   \\|      /                       2                       /     /                      2        2   \\
               |        4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/||   4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/|
               |        \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *sin|------------------------------------------||   \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *cos|------------------------------------------|
     re(f)     |im(f)                                                      \                    2                     /|                                                      \                    2                     /
x2 = ----- + I*|----- + -----------------------------------------------------------------------------------------------| + -----------------------------------------------------------------------------------------------
       8       \  8                                                    8                                               /                                                  8                                               
$$x_{2} = i \left(\frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{im}{\left(f\right)}}{8}\right) + \frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \cos{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{re}{\left(f\right)}}{8}$$
x2 = i*(((re(f)^2 - im(f)^2 + 32)^2 + 4*re(f)^2*im(f)^2)^(1/4)*sin(atan2(2*re(f)*im(f, re(f)^2 - im(f)^2 + 32)/2)/8 + im(f)/8) + ((re(f)^2 - im(f)^2 + 32)^2 + 4*re(f)^2*im(f)^2)^(1/4)*cos(atan2(2*re(f)*im(f), re(f)^2 - im(f)^2 + 32)/2)/8 + re(f)/8)
Suma y producto de raíces [src]
suma
          /            ___________________________________________                                                \       ___________________________________________                                                             /            ___________________________________________                                                \       ___________________________________________                                                
          |           /                       2                       /     /                      2        2   \\|      /                       2                       /     /                      2        2   \\             |           /                       2                       /     /                      2        2   \\|      /                       2                       /     /                      2        2   \\
          |        4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/||   4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/|             |        4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/||   4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/|
          |        \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *sin|------------------------------------------||   \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *cos|------------------------------------------|             |        \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *sin|------------------------------------------||   \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *cos|------------------------------------------|
re(f)     |im(f)                                                      \                    2                     /|                                                      \                    2                     /   re(f)     |im(f)                                                      \                    2                     /|                                                      \                    2                     /
----- + I*|----- - -----------------------------------------------------------------------------------------------| - ----------------------------------------------------------------------------------------------- + ----- + I*|----- + -----------------------------------------------------------------------------------------------| + -----------------------------------------------------------------------------------------------
  8       \  8                                                    8                                               /                                                  8                                                    8       \  8                                                    8                                               /                                                  8                                               
$$\left(i \left(- \frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{im}{\left(f\right)}}{8}\right) - \frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \cos{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{re}{\left(f\right)}}{8}\right) + \left(i \left(\frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{im}{\left(f\right)}}{8}\right) + \frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \cos{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{re}{\left(f\right)}}{8}\right)$$
=
          /            ___________________________________________                                                \     /            ___________________________________________                                                \
          |           /                       2                       /     /                      2        2   \\|     |           /                       2                       /     /                      2        2   \\|
          |        4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/||     |        4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/||
          |        \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *sin|------------------------------------------||     |        \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *sin|------------------------------------------||
re(f)     |im(f)                                                      \                    2                     /|     |im(f)                                                      \                    2                     /|
----- + I*|----- - -----------------------------------------------------------------------------------------------| + I*|----- + -----------------------------------------------------------------------------------------------|
  4       \  8                                                    8                                               /     \  8                                                    8                                               /
$$i \left(- \frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{im}{\left(f\right)}}{8}\right) + i \left(\frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{im}{\left(f\right)}}{8}\right) + \frac{\operatorname{re}{\left(f\right)}}{4}$$
producto
/          /            ___________________________________________                                                \       ___________________________________________                                                \ /          /            ___________________________________________                                                \       ___________________________________________                                                \
|          |           /                       2                       /     /                      2        2   \\|      /                       2                       /     /                      2        2   \\| |          |           /                       2                       /     /                      2        2   \\|      /                       2                       /     /                      2        2   \\|
|          |        4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/||   4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/|| |          |        4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/||   4 /  /       2        2   \        2      2        |atan2\2*im(f)*re(f), 32 + re (f) - im (f)/||
|          |        \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *sin|------------------------------------------||   \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *cos|------------------------------------------|| |          |        \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *sin|------------------------------------------||   \/   \32 + re (f) - im (f)/  + 4*im (f)*re (f) *cos|------------------------------------------||
|re(f)     |im(f)                                                      \                    2                     /|                                                      \                    2                     /| |re(f)     |im(f)                                                      \                    2                     /|                                                      \                    2                     /|
|----- + I*|----- - -----------------------------------------------------------------------------------------------| - -----------------------------------------------------------------------------------------------|*|----- + I*|----- + -----------------------------------------------------------------------------------------------| + -----------------------------------------------------------------------------------------------|
\  8       \  8                                                    8                                               /                                                  8                                               / \  8       \  8                                                    8                                               /                                                  8                                               /
$$\left(i \left(- \frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{im}{\left(f\right)}}{8}\right) - \frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \cos{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{re}{\left(f\right)}}{8}\right) \left(i \left(\frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{im}{\left(f\right)}}{8}\right) + \frac{\sqrt[4]{\left(\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32\right)^{2} + 4 \left(\operatorname{re}{\left(f\right)}\right)^{2} \left(\operatorname{im}{\left(f\right)}\right)^{2}} \cos{\left(\frac{\operatorname{atan_{2}}{\left(2 \operatorname{re}{\left(f\right)} \operatorname{im}{\left(f\right)},\left(\operatorname{re}{\left(f\right)}\right)^{2} - \left(\operatorname{im}{\left(f\right)}\right)^{2} + 32 \right)}}{2} \right)}}{8} + \frac{\operatorname{re}{\left(f\right)}}{8}\right)$$
=
-1/2
$$- \frac{1}{2}$$
-1/2