Question

why is 48 the answer for f(x) varies directly with x2, and f(x) = 75 when x = 5, find the value of f(4)

Answer 1

so with direct variation the equation is

\[f(x) = k \times x^2\]

so use the given information to find k...


\[75 = k \times 5^2\]

when you have k the equation becomes

\[f(4) = k \times 4^2\]