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If f(x)=12x,x2, find \(f^{-1}(-\fra...

If f(x)=12x,x2, find f1(12).

A.

4

B.

0

C.

-2

D.

-4

Correct answer is A

f(x)=12x,x2

f(y)=12y

x=12y (Let x = f(y))

2xxy=1y=2x1x

f^{-1}(-\frac{1}{2}) = \frac{2(-\frac{1}{2}) - 1}{-\frac{1}{2}}

= -2 \times -2 = 4