Question

Y is inversely proportional to the square of x. If Y = 9 when x = 2,then what is Y, when x is 10?9O 25OO252

Answer 1

Solution

Step 1

Y is inversely proportional to the square root of x.

$y\text{ = }\frac{k}{x^2}$

Step 2

Find the value of k if Y = 9 when x = 2.

$\begin{gathered} y\text{ = }\frac{k}{x^2} \\ \\ 9\text{ = }\frac{k}{2^2} \\ \\ k\text{ = 9}\times4\text{ = 36} \end{gathered}$

Step 3

What is Y, when x is 10?

$\begin{gathered} y\text{ = }\frac{36}{10^2} \\ \\ y\text{ = }\frac{36}{100} \\ \\ y\text{ = }\frac{9}{25} \end{gathered}$

Final answer

$\frac{9}{25}$