## anonymous one year ago MEDAL SOLVE (cos Θ − cos Θ)2 + (cos Θ + cos Θ)2

1. zepdrix

Hey there :) Unless your teacher wants you to do this a specific way, notice that you have a cosine minus cosine, which gives you zero there. And in the other brackets, simply combine your like-terms.$\Large\rm (\cos \theta-\cos \theta)^2+(\cos \theta+\cos \theta)^2$$\Large\rm (0)^2+(2\cos \theta)^2$

2. zepdrix

And then square both the 2, and the cosine.

3. anonymous

0 +2cos

4. zepdrix

No you still need to square the 2cos(theta).$\Large\rm (2\cos \theta)^2=2^2\cos^2\theta$

5. anonymous

8

6. anonymous

it is 4cos^2 theta

7. zepdrix

yes.