El profesor se sorprenderá mucho al ver tu solución correcta😉
cos(2*x) + 5*cos(x) + a = 0
a*w^2 + b*w + c = 0
D = b^2 - 4 * a * c =
(5)^2 - 4 * (2) * (-1 + a) = 33 - 8*a
w1 = (-b + sqrt(D)) / (2*a)
w2 = (-b - sqrt(D)) / (2*a)
/| ___________________________|\ || __________ ___ / __________ || / ___________________________\ || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a || | __________ ___ / __________ | x1 = - I*log||- - - ------------ - ------------------------------------|| + arg\-5 - \/ 33 - 8*a - \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a / \| 4 4 4 |/
/| ___________________________|\ || __________ ___ / __________ || / ___________________________\ || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a || | __________ ___ / __________ | x2 = - I*log||- - - ------------ + ------------------------------------|| + arg\-5 - \/ 33 - 8*a + \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a / \| 4 4 4 |/
/| ___________________________|\ || __________ ___ / __________ || / ___________________________\ || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a || | __________ ___ / __________ | x3 = - I*log||- - + ------------ - ------------------------------------|| + arg\-5 + \/ 33 - 8*a - \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a / \| 4 4 4 |/
/| ___________________________|\ || __________ ___ / __________ || / ___________________________\ || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a || | __________ ___ / __________ | x4 = - I*log||- - + ------------ + ------------------------------------|| + arg\-5 + \/ 33 - 8*a + \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a / \| 4 4 4 |/
x4 = -i*log(Abs(sqrt(33 - 8*a)/4 + sqrt(2)*sqrt(-4*a - 5*sqrt(33 - 8*a) + 21)/4 - 5/4)) + arg(sqrt(33 - 8*a) + sqrt(2)*sqrt(-4*a - 5*sqrt(33 - 8*a) + 21) - 5)
suma
/| ___________________________|\ /| ___________________________|\ /| ___________________________|\ /| ___________________________|\ || __________ ___ / __________ || / ___________________________\ || __________ ___ / __________ || / ___________________________\ || __________ ___ / __________ || / ___________________________\ || __________ ___ / __________ || / ___________________________\ || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a || | __________ ___ / __________ | || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a || | __________ ___ / __________ | || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a || | __________ ___ / __________ | || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a || | __________ ___ / __________ | - I*log||- - - ------------ - ------------------------------------|| + arg\-5 - \/ 33 - 8*a - \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a / + - I*log||- - - ------------ + ------------------------------------|| + arg\-5 - \/ 33 - 8*a + \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a / + - I*log||- - + ------------ - ------------------------------------|| + arg\-5 + \/ 33 - 8*a - \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a / + - I*log||- - + ------------ + ------------------------------------|| + arg\-5 + \/ 33 - 8*a + \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a / \| 4 4 4 |/ \| 4 4 4 |/ \| 4 4 4 |/ \| 4 4 4 |/
=
/| ___________________________|\ /| ___________________________|\ /| ___________________________|\ /| ___________________________|\ || __________ ___ / __________ || || __________ ___ / __________ || || __________ ___ / __________ || || __________ ___ / __________ || / ___________________________\ / ___________________________\ / ___________________________\ / ___________________________\ || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a || || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a || || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a || || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a || | __________ ___ / __________ | | __________ ___ / __________ | | __________ ___ / __________ | | __________ ___ / __________ | - I*log||- - - ------------ - ------------------------------------|| - I*log||- - - ------------ + ------------------------------------|| - I*log||- - + ------------ - ------------------------------------|| - I*log||- - + ------------ + ------------------------------------|| + arg\-5 + \/ 33 - 8*a + \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a / + arg\-5 + \/ 33 - 8*a - \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a / + arg\-5 - \/ 33 - 8*a + \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a / + arg\-5 - \/ 33 - 8*a - \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a / \| 4 4 4 |/ \| 4 4 4 |/ \| 4 4 4 |/ \| 4 4 4 |/
producto
/ /| ___________________________|\ \ / /| ___________________________|\ \ / /| ___________________________|\ \ / /| ___________________________|\ \ | || __________ ___ / __________ || / ___________________________\| | || __________ ___ / __________ || / ___________________________\| | || __________ ___ / __________ || / ___________________________\| | || __________ ___ / __________ || / ___________________________\| | || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a || | __________ ___ / __________ || | || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a || | __________ ___ / __________ || | || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a || | __________ ___ / __________ || | || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a || | __________ ___ / __________ || |- I*log||- - - ------------ - ------------------------------------|| + arg\-5 - \/ 33 - 8*a - \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a /|*|- I*log||- - - ------------ + ------------------------------------|| + arg\-5 - \/ 33 - 8*a + \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a /|*|- I*log||- - + ------------ - ------------------------------------|| + arg\-5 + \/ 33 - 8*a - \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a /|*|- I*log||- - + ------------ + ------------------------------------|| + arg\-5 + \/ 33 - 8*a + \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a /| \ \| 4 4 4 |/ / \ \| 4 4 4 |/ / \ \| 4 4 4 |/ / \ \| 4 4 4 |/ /
=
/ /| ___________________________|\\ / /| ___________________________|\\ / /| ___________________________|\\ / /| ___________________________|\\ | / ___________________________\ || __________ ___ / __________ ||| | / ___________________________\ || __________ ___ / __________ ||| | / ___________________________\ || __________ ___ / __________ ||| | / ___________________________\ || __________ ___ / __________ ||| | | __________ ___ / __________ | || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a ||| | | __________ ___ / __________ | || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a ||| | | __________ ___ / __________ | || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a ||| | | __________ ___ / __________ | || 5 \/ 33 - 8*a \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a ||| |- arg\-5 + \/ 33 - 8*a + \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a / + I*log||- - + ------------ + ------------------------------------|||*|- arg\-5 + \/ 33 - 8*a - \/ 2 *\/ 21 - 5*\/ 33 - 8*a - 4*a / + I*log||- - + ------------ - ------------------------------------|||*|- arg\-5 - \/ 33 - 8*a + \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a / + I*log||- - - ------------ + ------------------------------------|||*|- arg\-5 - \/ 33 - 8*a - \/ 2 *\/ 21 - 4*a + 5*\/ 33 - 8*a / + I*log||- - - ------------ - ------------------------------------||| \ \| 4 4 4 |// \ \| 4 4 4 |// \ \| 4 4 4 |// \ \| 4 4 4 |//
(-arg(-5 + sqrt(33 - 8*a) + sqrt(2)*sqrt(21 - 5*sqrt(33 - 8*a) - 4*a)) + i*log(Abs(-5/4 + sqrt(33 - 8*a)/4 + sqrt(2)*sqrt(21 - 5*sqrt(33 - 8*a) - 4*a)/4)))*(-arg(-5 + sqrt(33 - 8*a) - sqrt(2)*sqrt(21 - 5*sqrt(33 - 8*a) - 4*a)) + i*log(Abs(-5/4 + sqrt(33 - 8*a)/4 - sqrt(2)*sqrt(21 - 5*sqrt(33 - 8*a) - 4*a)/4)))*(-arg(-5 - sqrt(33 - 8*a) + sqrt(2)*sqrt(21 - 4*a + 5*sqrt(33 - 8*a))) + i*log(Abs(-5/4 - sqrt(33 - 8*a)/4 + sqrt(2)*sqrt(21 - 4*a + 5*sqrt(33 - 8*a))/4)))*(-arg(-5 - sqrt(33 - 8*a) - sqrt(2)*sqrt(21 - 4*a + 5*sqrt(33 - 8*a))) + i*log(Abs(-5/4 - sqrt(33 - 8*a)/4 - sqrt(2)*sqrt(21 - 4*a + 5*sqrt(33 - 8*a))/4)))