Se da la desigualdad:
$$\left(x - 3\right) \left(x - 1\right) \log{\left(\left(\cos{\left(x \right)} + \cos^{2}{\left(\pi x \right)}\right) + \frac{2 \sin^{\sqrt{\frac{11}{5}}}{\left(\frac{x}{2} \right)}}{2} \right)} \geq 2$$
Para resolver esta desigualdad primero hay que resolver la ecuación correspondiente:
$$\left(x - 3\right) \left(x - 1\right) \log{\left(\left(\cos{\left(x \right)} + \cos^{2}{\left(\pi x \right)}\right) + \frac{2 \sin^{\sqrt{\frac{11}{5}}}{\left(\frac{x}{2} \right)}}{2} \right)} = 2$$
Resolvemos:
$$x_{1} = 100.510435418134 - 0.0047674147312816 i$$
$$x_{2} = 68.5297227402575$$
$$x_{3} = -93.6529547362519 - 0.0504357558232563 i$$
$$x_{4} = 52.2132777167091$$
$$x_{5} = 94.4430446648741 + 0.0239734809090849 i$$
$$x_{6} = 40.1269090033684$$
$$x_{7} = -33.8796199609159$$
$$x_{8} = 8.08522178928987 + 0.221804327440013 i$$
$$x_{9} = 42.2523150363882$$
$$x_{10} = -87.4951623536677 + 0.0264918224471817 i$$
$$x_{11} = -61.6484065733173$$
$$x_{12} = -67.8271064885251 - 0.116532580524128 i$$
$$x_{13} = -41.919402019937 + 0.253793657662776 i$$
$$x_{14} = -83.8209630426373$$
$$x_{15} = -47.8674926836918$$
$$x_{16} = 90.1676573854581$$
$$x_{17} = -16.9160112621997 + 0.236091194526466 i$$
$$x_{18} = -7.69765946779217$$
$$x_{19} = 0.0259969878312562$$
$$x_{20} = 58.1159652901164 - 0.168943046399089 i$$
$$x_{21} = 28.0383674979943$$
$$x_{22} = 44.3912217448768 - 0.0386843113446253 i$$
$$x_{23} = 14.2557271704627$$
$$x_{24} = -57.6296158327081$$
$$x_{25} = -95.3640346092024$$
$$x_{26} = -95.6965840882506$$
$$x_{27} = 73.8767048669985 + 0.159634370423093 i$$
$$x_{28} = 56.5037427905596 + 0.0142885202923343 i$$
$$x_{29} = -5.66932787023074 - 0.0497064137401943 i$$
$$x_{30} = 88.519795836584$$
$$x_{31} = 26.3451765828346$$
$$x_{32} = -71.9446304817941$$
$$x_{33} = 92.1945249026872$$
$$x_{34} = 54.128574941131$$
$$x_{35} = -81.5428971975277 - 0.0191245612540122 i$$
$$x_{36} = 15.9671278777495$$
$$x_{37} = 80.3190541652628$$
$$x_{38} = -73.7353154660035$$
$$x_{39} = 64.2998397574696$$
$$x_{40} = 35.9079872393627 - 0.212205057974673 i$$
$$x_{41} = -52.089956603758 - 0.217871757172483 i$$
$$x_{42} = 32.2802458587386 - 0.0691505085823875 i$$
$$x_{43} = -66.9212508083606 + 0.269489880500199 i$$
$$x_{44} = 20.164782218209 - 0.121405581267706 i$$
$$x_{45} = 92.7122815315705$$
$$x_{46} = -99.6012951400255$$
$$x_{47} = 6.38590519069954 - 0.00575895418760668 i$$
$$x_{48} = -54.8953300391768 - 0.186195356732807 i$$
$$x_{49} = -31.4961106304242 - 0.0191707060545047 i$$
$$x_{50} = -14.1170844576311 - 0.166541967937758 i$$
$$x_{51} = -23.6954544888424$$
$$x_{52} = 82.3332156159097 - 0.0540938198971391 i$$
$$x_{53} = -29.8795040594379 - 0.162851569333039 i$$
$$x_{54} = -2.07254282841937 - 0.270802694872933 i$$
$$x_{55} = -17.7742905308476 - 0.0886248084834091 i$$
$$x_{56} = -19.4587884353761$$
$$x_{57} = -59.9535607517084$$
$$x_{58} = -45.7553208896104$$
$$x_{59} = 111.823557484907 + 0.114305309917005 i$$
$$x_{60} = 50.4985071395553 - 0.0369607780358167 i$$
$$x_{61} = 76.3874647847242$$
$$x_{62} = -35.7814970140969$$
$$x_{63} = 11.7207671633765 - 0.0672315020436625 i$$
$$x_{64} = -49.4130262826674$$
$$x_{65} = -75.4734559804639 - 0.0125866265148061 i$$
$$x_{66} = 3.28658644133219 - 0.369342697073948 i$$
$$x_{67} = 38.5957978455979$$
$$x_{68} = 5.30170266613166$$
$$x_{69} = -9.92049181202345$$
$$x_{70} = 85.9189522586373 - 0.251433509912749 i$$
$$x_{71} = -25.4194772379531 - 0.0303405831403926 i$$
$$x_{72} = -55.7122976199228 - 0.0670079176742718 i$$
$$x_{73} = -37.5022710508658 + 0.0343942270405407 i$$
$$x_{74} = 18.4984592764267 - 0.0265263451148552 i$$
$$x_{75} = -43.6019102829849 - 0.0368709510682677 i$$
$$x_{76} = -11.6114441043886$$
$$x_{77} = -97.9075682228443$$
$$x_{78} = 70.2194936875721 - 0.0917905796213954 i$$
$$x_{79} = -80.7389286380715 + 0.075669195211865 i$$
$$x_{80} = -40.9095455028656 - 0.321103912982183 i$$
$$x_{81} = -85.8215792771042$$
$$x_{82} = 62.5726892695298 - 0.0287324695214719 i$$
$$x_{83} = 12.543766196288 - 0.00146153110638568 i$$
$$x_{84} = 78.081604889231$$
Descartamos las soluciones complejas:
$$x_{1} = 68.5297227402575$$
$$x_{2} = 52.2132777167091$$
$$x_{3} = 40.1269090033684$$
$$x_{4} = -33.8796199609159$$
$$x_{5} = 42.2523150363882$$
$$x_{6} = -61.6484065733173$$
$$x_{7} = -83.8209630426373$$
$$x_{8} = -47.8674926836918$$
$$x_{9} = 90.1676573854581$$
$$x_{10} = -7.69765946779217$$
$$x_{11} = 0.0259969878312562$$
$$x_{12} = 28.0383674979943$$
$$x_{13} = 14.2557271704627$$
$$x_{14} = -57.6296158327081$$
$$x_{15} = -95.3640346092024$$
$$x_{16} = -95.6965840882506$$
$$x_{17} = 88.519795836584$$
$$x_{18} = 26.3451765828346$$
$$x_{19} = -71.9446304817941$$
$$x_{20} = 92.1945249026872$$
$$x_{21} = 54.128574941131$$
$$x_{22} = 15.9671278777495$$
$$x_{23} = 80.3190541652628$$
$$x_{24} = -73.7353154660035$$
$$x_{25} = 64.2998397574696$$
$$x_{26} = 92.7122815315705$$
$$x_{27} = -99.6012951400255$$
$$x_{28} = -23.6954544888424$$
$$x_{29} = -19.4587884353761$$
$$x_{30} = -59.9535607517084$$
$$x_{31} = -45.7553208896104$$
$$x_{32} = 76.3874647847242$$
$$x_{33} = -35.7814970140969$$
$$x_{34} = -49.4130262826674$$
$$x_{35} = 38.5957978455979$$
$$x_{36} = 5.30170266613166$$
$$x_{37} = -9.92049181202345$$
$$x_{38} = -11.6114441043886$$
$$x_{39} = -97.9075682228443$$
$$x_{40} = -85.8215792771042$$
$$x_{41} = 78.081604889231$$
Las raíces dadas
$$x_{27} = -99.6012951400255$$
$$x_{39} = -97.9075682228443$$
$$x_{16} = -95.6965840882506$$
$$x_{15} = -95.3640346092024$$
$$x_{40} = -85.8215792771042$$
$$x_{7} = -83.8209630426373$$
$$x_{24} = -73.7353154660035$$
$$x_{19} = -71.9446304817941$$
$$x_{6} = -61.6484065733173$$
$$x_{30} = -59.9535607517084$$
$$x_{14} = -57.6296158327081$$
$$x_{34} = -49.4130262826674$$
$$x_{8} = -47.8674926836918$$
$$x_{31} = -45.7553208896104$$
$$x_{33} = -35.7814970140969$$
$$x_{4} = -33.8796199609159$$
$$x_{28} = -23.6954544888424$$
$$x_{29} = -19.4587884353761$$
$$x_{38} = -11.6114441043886$$
$$x_{37} = -9.92049181202345$$
$$x_{10} = -7.69765946779217$$
$$x_{11} = 0.0259969878312562$$
$$x_{36} = 5.30170266613166$$
$$x_{13} = 14.2557271704627$$
$$x_{22} = 15.9671278777495$$
$$x_{18} = 26.3451765828346$$
$$x_{12} = 28.0383674979943$$
$$x_{35} = 38.5957978455979$$
$$x_{3} = 40.1269090033684$$
$$x_{5} = 42.2523150363882$$
$$x_{2} = 52.2132777167091$$
$$x_{21} = 54.128574941131$$
$$x_{25} = 64.2998397574696$$
$$x_{1} = 68.5297227402575$$
$$x_{32} = 76.3874647847242$$
$$x_{41} = 78.081604889231$$
$$x_{23} = 80.3190541652628$$
$$x_{17} = 88.519795836584$$
$$x_{9} = 90.1676573854581$$
$$x_{20} = 92.1945249026872$$
$$x_{26} = 92.7122815315705$$
son puntos de cambio del signo de desigualdad en las soluciones.
Primero definámonos con el signo hasta el punto extremo izquierdo:
$$x_{0} \leq x_{27}$$
Consideremos, por ejemplo, el punto
$$x_{0} = x_{27} - \frac{1}{10}$$
=
$$-99.6012951400255 + - \frac{1}{10}$$
=
$$-99.7012951400255$$
lo sustituimos en la expresión
$$\left(x - 3\right) \left(x - 1\right) \log{\left(\left(\cos{\left(x \right)} + \cos^{2}{\left(\pi x \right)}\right) + \frac{2 \sin^{\sqrt{\frac{11}{5}}}{\left(\frac{x}{2} \right)}}{2} \right)} \geq 2$$
$$\left(-99.7012951400255 - 3\right) \left(-99.7012951400255 - 1\right) \log{\left(\frac{2 \sin^{\sqrt{\frac{11}{5}}}{\left(- \frac{99.7012951400255}{2} \right)}}{2} + \left(\cos^{2}{\left(\left(-99.7012951400255\right) \pi \right)} + \cos{\left(-99.7012951400255 \right)}\right) \right)} \geq 2$$
/ ____ \
| \/ 55 |
| ------ | >= 2
| 5 2 |
10342.1534331586*log\0.675119406768933 + 0.403038827677351 + cos (1.70129514002545*pi)/
significa que una de las soluciones de nuestra ecuación será con:
$$x \leq -99.6012951400255$$
_____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____
\ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \
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x27 x39 x16 x15 x40 x7 x24 x19 x6 x30 x14 x34 x8 x31 x33 x4 x28 x29 x38 x37 x10 x11 x36 x13 x22 x18 x12 x35 x3 x5 x2 x21 x25 x1 x32 x41 x23 x17 x9 x20 x26
Recibiremos otras soluciones de la desigualdad pasando al polo siguiente etc.
etc.
Respuesta:
$$x \leq -99.6012951400255$$
$$x \geq -97.9075682228443 \wedge x \leq -95.6965840882506$$
$$x \geq -95.3640346092024 \wedge x \leq -85.8215792771042$$
$$x \geq -83.8209630426373 \wedge x \leq -73.7353154660035$$
$$x \geq -71.9446304817941 \wedge x \leq -61.6484065733173$$
$$x \geq -59.9535607517084 \wedge x \leq -57.6296158327081$$
$$x \geq -49.4130262826674 \wedge x \leq -47.8674926836918$$
$$x \geq -45.7553208896104 \wedge x \leq -35.7814970140969$$
$$x \geq -33.8796199609159 \wedge x \leq -23.6954544888424$$
$$x \geq -19.4587884353761 \wedge x \leq -11.6114441043886$$
$$x \geq -9.92049181202345 \wedge x \leq -7.69765946779217$$
$$x \geq 0.0259969878312562 \wedge x \leq 5.30170266613166$$
$$x \geq 14.2557271704627 \wedge x \leq 15.9671278777495$$
$$x \geq 26.3451765828346 \wedge x \leq 28.0383674979943$$
$$x \geq 38.5957978455979 \wedge x \leq 40.1269090033684$$
$$x \geq 42.2523150363882 \wedge x \leq 52.2132777167091$$
$$x \geq 54.128574941131 \wedge x \leq 64.2998397574696$$
$$x \geq 68.5297227402575 \wedge x \leq 76.3874647847242$$
$$x \geq 78.081604889231 \wedge x \leq 80.3190541652628$$
$$x \geq 88.519795836584 \wedge x \leq 90.1676573854581$$
$$x \geq 92.1945249026872 \wedge x \leq 92.7122815315705$$