1. ## Basic Cosine

Im having a brain fade here, and I know this is basic algebra, but cant remember how to do it. I need to solve for cos(theta)

1-cos(theta)=1+cos(theta)

2. Originally Posted by BCHurricane89
Im having a brain fade here, and I know this is basic algebra, but cant remember how to do it. I need to solve for cos(theta)

1-cos(theta)=1+cos(theta)

Add $cos(\theta)$ to both sides and then add $-1$ to both sides:
$2cos(\theta) = 0$
$\theta = \frac{\pi}{2} \pm k\pi$ where k is an integer