Posted by Mary on Monday, January 19, 2009 at 4:03am.
Graph the polar equation: 2=r cos(theta + 180)
2=r(costheta cos180+sintheta sin180)
2=r(1/2costheta +pi+ pi sintheta)
2=1/2rcostheta + pi rsintheta
2=1/2x+ pi y
4=x+ pi
0= x + pi4
how do i graph?

precalculus  Damon, Monday, January 19, 2009 at 6:19am
trig identity is
cos (a+b) = cos a cos b  sin a sin b
I think you have the sign wrong.
use pi radians for 180 deg
let t = theta
2 = r (cos t cos pi  sin t sin pi)
cos pi = 1 and sin pi = 0
2 = r ( cos t)
r cos t = 2
x = 2
vertical line through x = 2
note y = r sin t
so y = (2/cos t)sin t
y = 2 tan t
tan t takes all values from oo to +oo as t goes from 0 to 2 pi. In other words the entire vertical line.

precalculus  Mary, Monday, January 19, 2009 at 6:43am
Thank you I understand now.

xwao evroyiasq  xwao evroyiasq, Sunday, February 1, 2009 at 10:05pm
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