Find the exact solution of the equation.
\[
20 \cos ^{-1} x-4 \pi=4 \cos ^{-1} x
\]
The solution set is $\{\square$.
(Simplify your answer, including any radicals. Type an exact answer, using radicals as needed.)
\(\boxed{\{\frac{\sqrt{2}}{2}\}}\) is the final answer.
Step 1 :Given the equation \(20 \cos ^{-1} x-4 \pi=4 \cos ^{-1} x\).
Step 2 :Move the term with 'x' on one side and the constant term on the other side.
Step 3 :Solve the equation to isolate 'x'.
Step 4 :The solution to the equation is \(x = \frac{\sqrt{2}}{2}\).
Step 5 :\(\boxed{\{\frac{\sqrt{2}}{2}\}}\) is the final answer.