Question

if y = cos inverse x. Find d^2 y/ dx^2 in terms of y alone​

Answer 1

y=cos(-1x). = cos x

dy/dx = -sinx

d2y/dx2= -cosx

from y=cos(-x)

x=-cos–(y)

then

d2y/dx2=-cos {-cos–(y)}

d2y/dx2 = y