Q. If x = a (cos θ + log tan θ /2) and y = a sin θ , show that the value of d 2 y d x 2 a t θ = π 4 i s 4 a . Share with your friends Share 0 Aarushi Mishra answered this x=acos θ+log tan θ2dxdθ=ad dθcos θ+log tan θ2=a-sin θ+1tan θ2 sec2 θ2×12dxdθ=a-sin θ+cot θ2 sec2 θ2×12dxdθ=a-sin θ+cos θ2sin θ2 1cos2 θ2×12dxdθ=a-sin θ+12sin θ2cos θ2Use 2 sin x cos x= sin 2xdxdθ=a-sin θ+1sin θdxdθ=a1-sin2 θsin θdxdθ=acos2 θsin θy= a sin θdydθ=a cos θdydx=dydθdxdθ=a cos θacos2 θsin θ=sin θcos θ=tan θdydx=tan θd2ydx2=d dxtan θ=sec2θ dθdx=sec2θ 1dxdθ=sec2θ 1acos2 θsin θPut θ=π4d2ydx2=sec2π4 1acos2 π4sin π4=22 1a12212=21a12=22aPlease check your questoin. The final expression to prove is wrong 0 View Full Answer