What is the inverse function of $f (x) = \frac{1}{4} x + 7$ $f(x) =1/4x+7$ ?

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Answer 1 · 2015-07-01T23:03:55

$f^{- 1} (y) = 4 (y - 7)$ $f^-1(y) = 4(y-7)$ is the inverse function.

Let $y = f (x) = \frac{1}{4} x + 7$ $y = f(x) = 1/4x+7$

Subtract $7$ $7$ from both ends to get:

$y - 7 = \frac{1}{4} x$ $y - 7 = 1/4x$

Multiply both sides by $4$ $4$ to get:

$4 (y - 7) = x$ $4(y-7) = x$

So $f^{- 1} (y) = 4 (y - 7)$ $f^-1(y) = 4(y-7)$ is the inverse.

What is the inverse function of f(x) =1/4x+7f(x)=14x+7f(x) =1/4x+7?