Question

The function f(x) varies inversely with x and f(x) = 4 when x = 12.

Answer 1

Seriously know the answer, its 16, not 1. Just did it.

Answer 2

Answer: C. 16.

Step-by-step explanation:

We are given inverse relation between f(x) and x.

The function f(x) varies inversely with x.

Inverse relation could be written as

f(x) = $\frac{k}{x}$.

We also given f(x) = 4 when x = 12.

Plugging f(x) = 4 and x=12 in the above inverse relation to get the value of constant k.

$4=\frac{k}{12}$.

On cross multiplying, we get

12× 4 = $12 \times \frac{k}{12}$

48 = k

Now, we need to find f(x) for x=3.

Plugging k=48 and x=3 in inverse relation, we get

$f(x) = \frac{48}{3} = 16$.

Therefore, f(x)=16 when x=3.