86515 If ∫01tan−1xdx=p then ∫01tan−1(1−x1+x)dx=
(C) : Given,∫01tan−1xdx=pThen, ∫01tan−1(1−x1+x)dx=∫01[tan−1(1)−tan−1x]dx=∫01tan−1(1)dx−∫01tan−1xdx=π4[x]01−p=π4[1−0]−p=π4−p
86516 ∫0π/2sinx+cosx1+sin2xdx=
(C) : I=∫0π/2sinx+cosx1+sin2xdxI=∫0π/2sinx+cosxsin2x+cos2x+2sinxcosxdxI=∫0π/2sinx+cosx(sinx+cosx)2dxI=∫0π/2dx=[x]0π/2=π2−0So, I=π2
86517 ∫0π/211+tanxdx=
(A) : Given,I=∫0π/211+tanxdxI=∫0π/211+tan(π2−x)dxI=∫0π/2dx1+cotx=∫0π/211+1tanxdxI=∫0π/211+1tanxdxI=∫0π/2tanx1+tanxdxOn adding equation (i) and (ii), we get-2I=∫0π/21+tanx1+tanxdx=∫0π/21dx2I=[x]0π/2⇒I=π4
86518 The value of ∫0π/2log(tanx)dx is
(C) : Let,I=∫0π/2log(tanx)dxApply rule-I=∫0π/2logtan(π2−x)dx=∫0π/2logcotxdxOn adding equation (i) and (ii), we get -2I=∫0π/2log(tanx×cotx)dx=∫0π/2log1dx=0