Question

x varies inversely as y2, and x = 3 when y = 10. Find x when y = 5. A) x = 18 B) x = 2 C) x = 12 D) x = 75

Answer 1

The value of x is 12

Explanation:

We have the following function according to the statement:

`y^2=k\cdot(1)/(x)`

We first calculate the value of k, replacing (y = 10 and x = 3) and solving for k:

`\begin{gathered} 10^2=k\cdot(1)/(3) \\ k\cdot(1)/(3)=100 \\ k=300 \end{gathered}`

Since we have the value of k, we can plug in the value of k = 300 and of y = 5 to calculate the new value of x, just like this:

`\begin{gathered} 5^2=300\cdot(1)/(x) \\ x=(300)/(25) \\ x=12 \end{gathered}`