Chapter 8.1, Problem 44E

To determine

To convert the given equation to polar form -

  $x^2+y^2=9$

Answer to Problem 44E

The polar equation is $r=3$ .

Explanation of Solution

Given: Equation: $x^2+y^2=9$

Formula Used:

A polar equation is any equation that describes a relation between r and θ , where r represents the distance from the pole (origin) to a point on a curve, and θ represents the counter-clockwise angle made by a point on a curve, the pole, and the positive x-axis.

Also, $x=r\cos \theta$ and $y=r\sin \theta$

  $r=\sqrt{x^2+y^2}$ and $\theta ={\tan }^{-1}\left(\frac{y}{x}\right)$

Calculation:

Given equation is $x^2+y^2=9$

Using the above definition, we have:

  $r^2=9$

  $r=3$

Thus, the polar equation is $r=3$ .

Conclusion:

The polar equation is $r=3$ .