# The shutter speed s, of a camera varies inversely as the square of the aperture setting f. When f= 8, s= 125, how do you calculate the value of s when f=4?

May 16, 2017

$s = 250$

#### Explanation:

If two variables are inversely proportional, multiplying the two variables together would give a constant no matter how you change the two variables. That means that:

${f}_{1} {s}_{1} = {f}_{2} {s}_{2}$

Plug into the values. Call ${s}_{2}$ s:

$\left(8\right) \left(125\right) = \left(4\right) \left(s\right)$

Solve for $s$:

$s = 250$