Given that (f(x) = frac{x+1}{2}), find (f^{1}(-2)).
-
A.
-5 -
B.
-3 -
C.
(-frac{1}{2}) -
D.
5
Correct Answer: Option A
Explanation
Let (f(x) = y), then we have
(y = frac{x+1}{2} implies 2y = x+1; x = 2y-1)
Let (f^{1}(x) = x; x = 2y-1), replacing y with x,
(f^{1}(x) = 2x – 1 implies f^{1}(-2) = 2(-2) -1= -5)