Solve for r
r=\frac{a^{2}}{36}
a\geq 0
Solve for a
a=6\sqrt{r}
r\geq 0
Share
Copied to clipboard
6\sqrt{r}=a
Swap sides so that all variable terms are on the left hand side.
\frac{6\sqrt{r}}{6}=\frac{a}{6}
Divide both sides by 6.
\sqrt{r}=\frac{a}{6}
Dividing by 6 undoes the multiplication by 6.
r=\frac{a^{2}}{36}
Square both sides of the equation.
Examples
Quadratic equation
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}