Question

What is the universe of f(x)=3/4x

Answer 1

I assume you mean the inverse function. To find the inverse function of a given function, start from the expression $y = f(x)$ and solve for x:

$y = \dfrac{3}{4} x$

Multiply both sides by 4:

$4y = 3x$

Divide both sides by 3:

$\dfrac{4}{3}y = x$

So this is the inverse function.