## Precalculus (6th Edition) Blitzer

$\left( -2.019,3.453 \right)$
To determine rectangular coordinate from polar coordinate, follow the steps below: Step I: Press 2nd and then press APPS key to open the Angle Menu. Step II: Press 7 to select option. Step III: Enter the point $\left( r,\theta \right)$ and press enter to display x in the $\left( x,y \right)$ rectangular form of the point. Thus, $x=-2.019$ Step IV: Follow Step I and Step II and then press 8. Step V: Enter the point $\left( r,\theta \right)$ and press enter to display y in the $\left( x,y \right)$ rectangular form of the point. Thus, $y=3.453$ Hence, the rectangular coordinate of $\left( 4,\frac{2\pi }{3} \right)$ is $\left( -2.019,3.453 \right)$.