Question

Assume that y varies inversely with the

square of x, then solve.
When x is 5, y is 4/5. Find y when x is 8.

Answer 1

y = 5/16

Explanation:

`y\ \alpha\ (1)/(x^2)\\\\y = k * (1)/(x^2)\\\\y = (4)/(5), x = 5.\\\\(4)/(5) = k * (1)/(5^2)\\\\(4)/(5) * 5^2 = k\\\\20 = k\\\\Now \ find\ y, \ when \ x = 8\\\\y = k * (1)/(x^2) = 20 * (1)/(8^2) = 20 * (1)/(64) = (5)/(16)`