Question

Suppose that y varies inversely with x. Use the information to find k, and then choose the equation of variation. x = 1.2 when y = 3.

Answer 1

`\bf \qquad \qquad \textit{inverse proportional variation} \\\\ \textit{\underline{y} varies inversely with \underline{x}}\qquad \qquad y=\cfrac{k}{x}\impliedby \begin{array}{llll} k=constant\ of\\ \qquad variation \end{array}\\\\ -------------------------------\\\\ \textit{we also know that } \begin{cases} x=1.2\\ y=3 \end{cases}\implies 3=\cfrac{k}{1.2}\implies 3(1.2)=k \\\\\\ 3.6=k\qquad therefore\qquad y=\cfrac{3.6}{x}`