Determine the two equations necessary to graph the ellipse with a graphing calculator.
-$$\frac { x ^ { 2 } } { 81 } + \frac { y ^ { 2 } } { 64 } = 1$$
A) $y = \frac { 8 \sqrt { 81 - x ^ { 2 } } } { 9 }$ and $y = - \frac { 8 \sqrt { 81 - x ^ { 2 } } } { 9 }$

B) $x = \sqrt { \frac { 576 - x ^ { 2 } } { 8 } }$ and $x = - \sqrt { \frac { 576 - y ^ { 2 } } { 8 } }$

C) $\mathrm { y } = \frac { 8 \sqrt { 81 - \mathrm { x } ^ { 2 } } } { 81 }$ and $\mathrm { y } = - \frac { 8 \sqrt { 81 + \mathrm { x } ^ { 2 } } } { 81 }$

D) $x = \frac { 9 \sqrt { 81 - y ^ { 2 } } } { 64 }$ and $x = - \frac { 9 \sqrt { 81 - y ^ { 2 } } } { 64 }$

Question

Determine the two equations necessary to graph the ellipse with a graphing calculator.
-$$\frac { x ^ { 2 } } { 81 } + \frac { y ^ { 2 } } { 64 } = 1$$
A) $y = \frac { 8 \sqrt { 81 - x ^ { 2 } } } { 9 }$ and $y = - \frac { 8 \sqrt { 81 - x ^ { 2 } } } { 9 }$

B) $x = \sqrt { \frac { 576 - x ^ { 2 } } { 8 } }$ and $x = - \sqrt { \frac { 576 - y ^ { 2 } } { 8 } }$

C) $\mathrm { y } = \frac { 8 \sqrt { 81 - \mathrm { x } ^ { 2 } } } { 81 }$ and $\mathrm { y } = - \frac { 8 \sqrt { 81 + \mathrm { x } ^ { 2 } } } { 81 }$

D) $x = \frac { 9 \sqrt { 81 - y ^ { 2 } } } { 64 }$ and $x = - \frac { 9 \sqrt { 81 - y ^ { 2 } } } { 64 }$

Quizplus · Accepted Answer

To graph the ellipse on a calculator, you need to solve for $y$ in terms of $x$. Solving the given equation for $y$, you get $y = \pm \frac{8}{9}\sqrt{81 - x^2}$, which matches choice A.

Determine the Two Equations Necessary to Graph the Ellipse with a Graphing