Question

write the equation for the inverse of the function y=cos2x

Answer 1

the answer is basically A

Answer 2

we are given

$y=cos(2x)$

Since, we have to find inverse function

so, we will use following steps

step-1:

Set y=f(x)

It is already there

step-2:

Switch x and y

$x=cos(2y)$

step-3:

Solve for y

$x=cos(2y)$

we can take cos^-1 both sides

$cos^{-1}(x)=cos^{-1}(cos(2y))$

now, we can simplify it

$cos^{-1}(x)=2y$

Divide both sides by 2

$y=\frac{cos^{-1}(x)}{2}$

so, option-D........Answer