WAEC - Mathematics (2005 - No. 43)
If y \(\alpha\) x\(^2\) and y = 1\(\frac{1}{4}\) when x = 4, find the value of y when x = \(\frac{1}{2}\)
\(2\frac{1}{2}\)
5
10
80
توضیح
y \(\propto x^2\), y = 1\(\frac{1}{4}\), x = 4
y = \(\frac{\text{k}}{x^2}\)
k = y x\(^2\) = \(\frac{5}{4}\) x 4\(^2\) = 20
y = \(\frac{20}{x^2}\) = \(\frac{20}{x^2}\) = \(\frac{20}{(\frac{1}{2})^2}\)
= \(\frac{20}{\frac{1}{4}}\) = 20 x 4 = 80