# Math

Rewrite in rectangular form: r=6 cos theta
I got (x-3)^2+y^2=6

1. 👍
2. 👎
3. 👁

r=6 cos Ø
recall that cosØ = x/r

r = 6x/r
r^2 = 6x , recall that r^2 = x^2 + y^2
x^2 + y^2 = 6x
x^2 - 6x + 9 + y^2 = 9
(x-3)^2 + y^2 = 9

check:
polar plot: http://www.wolframalpha.com/input/?i=polar+plot+r%3D6+cos+%C3%98
cartesian plot: http://www.wolframalpha.com/input/?i=plot+(x-3)%5E2+%2B+y%5E2+%3D+9

1. 👍
2. 👎
2. Thank you :)

1. 👍
2. 👎

## Similar Questions

1. ### Precalculus check answers help!

1.) Find an expression equivalent to sec theta sin theta cot theta csc theta. tan theta csc theta sec theta ~ sin theta 2.) Find an expression equivalent to cos theta/sin theta . tan theta cot theta ~ sec theta csc theta 3.)

2. ### trig

If sin theta is equal to 5/13 and theta is an angle in quadrant II find the value of cos theta, sec theta, tan theta, csc theta, cot theta.

3. ### math

rewrite the given equation using the substitutions x=r cos theta and y=r sin theta. Simplify your answer. x^2+y^2+3x=0

4. ### Pre-Calculus HELP!

change the polar equation r=5/1+cos(theta) to rectangular form. How do I do this? Thank you! :)

1. ### Precalculus

Circle O below has radius 1. Eight segment lengths are labeled with lowercase letters. Six of these equal a trigonometric function of theta. Your answer to this problem should be a six letter sequence whose letters represent the

2. ### math (trig)

if cos 2 theta = -(1/3) and theta is in Quadrant 2, find sin theta, cos theta, tan theta, and draw triangle theta

3. ### Trig

Which expression equivalent to: cos(theta + pi/2). A)cos theta B)-cos theta C)sin theta D)-sin theta my book doesnt give examples of this but my crack at it would be C b/c distributive property? and 2cos theta = sin theta

4. ### MATHS TRIGONOMETRY

if 3sin theta =2 and cos greater than 0,with the aid of a diagram determine the value of: a) tan theta b) sin theta/cos theta c) sin^2 theta + cos^2 theta

1. ### Maths

a) Express f(theta) = 4cos theta - 6sin theta in the form r cos(theta + alpha) b) Hence find the general solution of the equation 4cos theta - 6sin theta =5 c) Hence, find the minimum value of the function 1/4+f( theta)