Se da la desigualdad:
$$3 + 3^{- x} > 3$$
Para resolver esta desigualdad primero hay que resolver la ecuación correspondiente:
$$3 + 3^{- x} = 3$$
Resolvemos:
$$x_{1} = 91.2951886379681$$
$$x_{2} = 93.2951886379681$$
$$x_{3} = 47.295188637968$$
$$x_{4} = 59.295188637968$$
$$x_{5} = 87.2951886379681$$
$$x_{6} = 45.295188637968$$
$$x_{7} = 71.2951886379681$$
$$x_{8} = 61.295188637968$$
$$x_{9} = 95.2951886379681$$
$$x_{10} = 65.2951886379681$$
$$x_{11} = 117.295188637968$$
$$x_{12} = 69.2951886379681$$
$$x_{13} = 67.2951886379681$$
$$x_{14} = 43.295188637968$$
$$x_{15} = 25.295188637968$$
$$x_{16} = 79.2951886379681$$
$$x_{17} = 51.295188637968$$
$$x_{18} = 99.2951886379681$$
$$x_{19} = 31.295188637968$$
$$x_{20} = 49.295188637968$$
$$x_{21} = 113.295188637968$$
$$x_{22} = 77.2951886379681$$
$$x_{23} = 33.295188637968$$
$$x_{24} = 41.295188637968$$
$$x_{25} = 107.295188637968$$
$$x_{26} = 103.295188637968$$
$$x_{27} = 83.2951886379681$$
$$x_{28} = 35.295188637968$$
$$x_{29} = 27.295188637968$$
$$x_{30} = 97.2951886379681$$
$$x_{31} = 37.295188637968$$
$$x_{32} = 63.295188637968$$
$$x_{33} = 85.2951886379681$$
$$x_{34} = 111.295188637968$$
$$x_{35} = 109.295188637968$$
$$x_{36} = 81.2951886379681$$
$$x_{37} = 29.295188637968$$
$$x_{38} = 75.2951886379681$$
$$x_{39} = 119.295188637968$$
$$x_{40} = 115.295188637968$$
$$x_{41} = 55.295188637968$$
$$x_{42} = 53.295188637968$$
$$x_{43} = 101.295188637968$$
$$x_{44} = 39.295188637968$$
$$x_{45} = 105.295188637968$$
$$x_{46} = 73.2951886379681$$
$$x_{47} = 57.295188637968$$
$$x_{48} = 89.2951886379681$$
$$x_{1} = 91.2951886379681$$
$$x_{2} = 93.2951886379681$$
$$x_{3} = 47.295188637968$$
$$x_{4} = 59.295188637968$$
$$x_{5} = 87.2951886379681$$
$$x_{6} = 45.295188637968$$
$$x_{7} = 71.2951886379681$$
$$x_{8} = 61.295188637968$$
$$x_{9} = 95.2951886379681$$
$$x_{10} = 65.2951886379681$$
$$x_{11} = 117.295188637968$$
$$x_{12} = 69.2951886379681$$
$$x_{13} = 67.2951886379681$$
$$x_{14} = 43.295188637968$$
$$x_{15} = 25.295188637968$$
$$x_{16} = 79.2951886379681$$
$$x_{17} = 51.295188637968$$
$$x_{18} = 99.2951886379681$$
$$x_{19} = 31.295188637968$$
$$x_{20} = 49.295188637968$$
$$x_{21} = 113.295188637968$$
$$x_{22} = 77.2951886379681$$
$$x_{23} = 33.295188637968$$
$$x_{24} = 41.295188637968$$
$$x_{25} = 107.295188637968$$
$$x_{26} = 103.295188637968$$
$$x_{27} = 83.2951886379681$$
$$x_{28} = 35.295188637968$$
$$x_{29} = 27.295188637968$$
$$x_{30} = 97.2951886379681$$
$$x_{31} = 37.295188637968$$
$$x_{32} = 63.295188637968$$
$$x_{33} = 85.2951886379681$$
$$x_{34} = 111.295188637968$$
$$x_{35} = 109.295188637968$$
$$x_{36} = 81.2951886379681$$
$$x_{37} = 29.295188637968$$
$$x_{38} = 75.2951886379681$$
$$x_{39} = 119.295188637968$$
$$x_{40} = 115.295188637968$$
$$x_{41} = 55.295188637968$$
$$x_{42} = 53.295188637968$$
$$x_{43} = 101.295188637968$$
$$x_{44} = 39.295188637968$$
$$x_{45} = 105.295188637968$$
$$x_{46} = 73.2951886379681$$
$$x_{47} = 57.295188637968$$
$$x_{48} = 89.2951886379681$$
Las raíces dadas
$$x_{15} = 25.295188637968$$
$$x_{29} = 27.295188637968$$
$$x_{37} = 29.295188637968$$
$$x_{19} = 31.295188637968$$
$$x_{23} = 33.295188637968$$
$$x_{28} = 35.295188637968$$
$$x_{31} = 37.295188637968$$
$$x_{44} = 39.295188637968$$
$$x_{24} = 41.295188637968$$
$$x_{14} = 43.295188637968$$
$$x_{6} = 45.295188637968$$
$$x_{3} = 47.295188637968$$
$$x_{20} = 49.295188637968$$
$$x_{17} = 51.295188637968$$
$$x_{42} = 53.295188637968$$
$$x_{41} = 55.295188637968$$
$$x_{47} = 57.295188637968$$
$$x_{4} = 59.295188637968$$
$$x_{8} = 61.295188637968$$
$$x_{32} = 63.295188637968$$
$$x_{10} = 65.2951886379681$$
$$x_{13} = 67.2951886379681$$
$$x_{12} = 69.2951886379681$$
$$x_{7} = 71.2951886379681$$
$$x_{46} = 73.2951886379681$$
$$x_{38} = 75.2951886379681$$
$$x_{22} = 77.2951886379681$$
$$x_{16} = 79.2951886379681$$
$$x_{36} = 81.2951886379681$$
$$x_{27} = 83.2951886379681$$
$$x_{33} = 85.2951886379681$$
$$x_{5} = 87.2951886379681$$
$$x_{48} = 89.2951886379681$$
$$x_{1} = 91.2951886379681$$
$$x_{2} = 93.2951886379681$$
$$x_{9} = 95.2951886379681$$
$$x_{30} = 97.2951886379681$$
$$x_{18} = 99.2951886379681$$
$$x_{43} = 101.295188637968$$
$$x_{26} = 103.295188637968$$
$$x_{45} = 105.295188637968$$
$$x_{25} = 107.295188637968$$
$$x_{35} = 109.295188637968$$
$$x_{34} = 111.295188637968$$
$$x_{21} = 113.295188637968$$
$$x_{40} = 115.295188637968$$
$$x_{11} = 117.295188637968$$
$$x_{39} = 119.295188637968$$
son puntos de cambio del signo de desigualdad en las soluciones.
Primero definámonos con el signo hasta el punto extremo izquierdo:
$$x_{0} < x_{15}$$
Consideremos, por ejemplo, el punto
$$x_{0} = x_{15} - \frac{1}{10}$$
=
$$- \frac{1}{10} + 25.295188637968$$
=
$$25.195188637968$$
lo sustituimos en la expresión
$$3 + 3^{- x} > 3$$
$$3^{- 25.195188637968} + 3 > 3$$
3.00000000000095 > 3
significa que una de las soluciones de nuestra ecuación será con:
$$x < 25.295188637968$$
_____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____
\ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ /
-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------
x15 x29 x37 x19 x23 x28 x31 x44 x24 x14 x6 x3 x20 x17 x42 x41 x47 x4 x8 x32 x10 x13 x12 x7 x46 x38 x22 x16 x36 x27 x33 x5 x48 x1 x2 x9 x30 x18 x43 x26 x45 x25 x35 x34 x21 x40 x11 x39
Recibiremos otras soluciones de la desigualdad pasando al polo siguiente etc.
etc.
Respuesta:
$$x < 25.295188637968$$
$$x > 27.295188637968 \wedge x < 29.295188637968$$
$$x > 31.295188637968 \wedge x < 33.295188637968$$
$$x > 35.295188637968 \wedge x < 37.295188637968$$
$$x > 39.295188637968 \wedge x < 41.295188637968$$
$$x > 43.295188637968 \wedge x < 45.295188637968$$
$$x > 47.295188637968 \wedge x < 49.295188637968$$
$$x > 51.295188637968 \wedge x < 53.295188637968$$
$$x > 55.295188637968 \wedge x < 57.295188637968$$
$$x > 59.295188637968 \wedge x < 61.295188637968$$
$$x > 63.295188637968 \wedge x < 65.2951886379681$$
$$x > 67.2951886379681 \wedge x < 69.2951886379681$$
$$x > 71.2951886379681 \wedge x < 73.2951886379681$$
$$x > 75.2951886379681 \wedge x < 77.2951886379681$$
$$x > 79.2951886379681 \wedge x < 81.2951886379681$$
$$x > 83.2951886379681 \wedge x < 85.2951886379681$$
$$x > 87.2951886379681 \wedge x < 89.2951886379681$$
$$x > 91.2951886379681 \wedge x < 93.2951886379681$$
$$x > 95.2951886379681 \wedge x < 97.2951886379681$$
$$x > 99.2951886379681 \wedge x < 101.295188637968$$
$$x > 103.295188637968 \wedge x < 105.295188637968$$
$$x > 107.295188637968 \wedge x < 109.295188637968$$
$$x > 111.295188637968 \wedge x < 113.295188637968$$
$$x > 115.295188637968 \wedge x < 117.295188637968$$
$$x > 119.295188637968$$