((cos^-1 (x))^2) - (sin^-1 (x)^2) = ?

1 Answer
Apr 16, 2018

#picos^(-1)x-pi^2/4#

Explanation:

We know that :

#cos^-1 x + sin^-1 x = pi/2#

#rArr sin^-1 x = pi/2 -cos^-1 x #...........................#(1)#

Put the value of #(1)# in the question , we get :-

#(cos^-1 x)^2 - (sin^-1 x)^2 = (cos^-1 x)^2 - (pi/2 -cos^-1 x )^2#

#= (cos^-1 x)^2 -pi^2/4-(cos^-1 x)^2+picos^-1 x#

#=cancel ((cos^-1 x)^2) -pi^2/4-cancel((cos^-1 x)^2)+picos^-1 x#

#=picos^-1 x-pi^2/4#