Solve for x:


To find: value of x


Given:


LHS = cos(sin-1 x) … (1)


Let sin θ = x


Therefore θ = sin-1 x … (2)



From the figure,


… (3)


From (2) and (3),


… (4)


Substituting (4) in (1), we get


LHS



Therefore,


Squaring and simplifying,


81 – 81x2 = 1


81x2 = 80




Therefore, are the required values of x.


1