if y is inversely proportional to x^2 and y=46 when x=20, find y if x=18.

Question

if is inversely proportional to and when , find if .

Answer 1

Inverse variation means:

y₁ x₁² = y₂ x₂² ⇒

y₂ = y₁ (x₁ / x₂)²

x₁ = 20

y₁ = 46

x₂ = 18

Plug these values into the equation above and get y₂.