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`int(e^(cotx))/(sin^(2)x)("2 ln cosec x"+sin2x)dx`A. `2e^(cotx)ln |sinx|+c`B. `2e^(tanx)ln|sinx|+c`C. `2e^(cotx)ln|cosx|+c`D. `2e^(tanx)ln |cosx|+c` |
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Answer» Correct Answer - A `t=cotxrArrdt=-"cosec"^(2)xdx` `I=int(e^(cotx))/(sin^(2)x)(ln" cosec"^(2)x+(2tanx)/(1+tan^(2)x))dx` `=-inte^(t)(ln(1+t^(2))+((2)/(t))/(1+(1)/t^(2)))dt` `=-e^(t)ln|1+t^(2)|+c=-2e^(cotx)ln|"cosec x"|+c` `=2e^(cotx)ln|sinx|+c` |
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