Write an equation to describe the variation. Use k for the constant of proportionality.
-$r$ varies jointly as the square of s and the square of $t$.
A) $r = k s ^ { 2 } t ^ { 2 }$
B) $r + s ^ { 2 } + t ^ { 2 } = k$
C) $r = k + s ^ { 2 } + t ^ { 2 }$
D) $r s ^ { 2 } t ^ { 2 } = k$

Question

Quizplus · Accepted Answer

Joint variation means that $r$ is directly proportional to both $s^2$ and $t^2$, which is correctly represented by $r = k s^2 t^2$.

Write an Equation to Describe the Variation rrr Varies Jointly as the Square of S and the Square

Write an Equation to Describe the Variation $r$ Varies Jointly as the Square of S and the Square