1.

`int(3+2cosx)/((2+3cosx)^(2))dx` is equal toA. `((sinx)/(2+3cosx))+C`B. `((2cosx)/(2+3sinx))+C`C. `((2cosx)/(2+3cosx))+C`D. `((2sinx)/(2+3sinx))+C`

Answer» Correct Answer - A
Divide numerator and denominator by `sin^(2)x`, then
`int(("3 cosec"^(2)x+"2 cosec x cot x"))/(("2 cosec x "+3 cot x)^(2))dx`
Put `" 2 cosec x "+"3 cot x = t`
` therefore" "(-"2 cosec x cot x "-"3 cosec"^(2)x)dx=dt`
`=int-(dt)/(t^(2))=(1)/(t)+C=(1)/("2 cosec x"+"3 cot x")+C`
`=(sinx)/((2+3 cos x))+C`


Discussion

No Comment Found