# How to factor these two problems?

• Oct 5th 2012, 01:07 AM
TWN
How to factor these two problems?
Find the tangents at the pole when r = -sin(5(theta))

For this problem I am going to need to factor the following:

1.) -cos(6(theta)) + sin(6(theta)) = 0

2.) -sin(5(theta)cos(theta)) - cos(5(theta)sin(theta)) = 0

Totally stuck. Someone show me how to do it please. Thank you!
• Oct 5th 2012, 01:21 AM
chiro
Re: How to factor these two problems?
Hey TWN.

Recall that tan(x) = sin(x)/cos(x) and that you can get the inverse of the argument of tan in the principal branch (-pi/2,pi/2) by using arc-tan.

For the second one you will need to go "deeper" in finding 5(theta)cos(theta) in terms of a constant and then finding theta from that.
• Oct 5th 2012, 01:32 AM
a tutor
Re: How to factor these two problems?
Quote:

Originally Posted by TWN
Find the tangents at the pole when r = -sin(5(theta))

For this problem I am going to need to factor the following: ...

Why? r=0 when theta = 0, pi/5, 2pi/5.....