Question

What is (cos Θ − cos Θ)^2 + (cos Θ + cos Θ)^2?

sin^2 Θ
4cos^2 Θ
8
cos^2 Θ

Answer 1

cos theta - cos theta = ?

Answer 2

it's like saying x - x, what does that give you?

Answer 3

I know that part equals out to 0, but then I'm left with (cos theta + cos theta)^2

Answer 4

I can't figure that out :(

Answer 5

Oh but in your case, there's a right answer yay!

Answer 6

It becomes \[\cos ^{2}\theta + \cos ^{2}\theta\]

Answer 7

Expand? 0_o
But you said x-x = 0
why not apply that thinking to the other one?
x+x = 2x

Answer 8

That's why I'm confused, it can't just equal 2x

Answer 9

...?

Answer 10

The other one is x+x

Answer 11

the (cos theta+ cos theta)^2 term

Answer 12

cos theta + cos theta = 2cos theta, now square it

Answer 13

Ohhh

Answer 14

Well then it would be \[4\cos^2 \theta\]

Answer 15

Well I'm an idiot

Answer 16

It was simple... -_-

Answer 17

Lol, don't worry for some reason I was thinking costheta+ sintheta

Answer 18

But in any case if you took long way or just added right away, you'd get same answer

Answer 19

It's okay, thank you for helping though!

Answer 20

Yw :)