Question

X varies directly as the square of Y. If X = 1 when Y = 2, then find the constant of variation.

• A. 0.25
• B. 0.3
• C. 0.5
• D. 0.75

Answer 1

The correct option is A 0.25

Let the constant of variation be k.
Given, X varies directly as as the square of Y.
$\Rightarrow X\propto Y^2$
$\Rightarrow X=k{Y}^2$
Given, at X = 1, Y = 2.
So, $k=\frac{X}{Y^2}=\frac{1}{2^2}=\frac{1}{4}=0.25$