The function f(x)=x -3 is one-to-one. a. Find an equation for f1, the inverse function. b. Verify that your equation is correct by showing that f(f(x)) =x and f1 (f(x)) = x. a. Select the correct choice below and fill in the answer box(es) to complete your choice. (Simplify your answer. Use integers or fractions for any numbers in the expression.) A. f(x)= for x B. f(x)=for xs OB. OC. f(x)= for all x OD. f(x)= for x