Question

(cos Θ − cos Θ)^2 + (cos Θ + cos Θ)^2

Answer 1

Simplify

Answer 2

@mathstudent55

Answer 3

@GreenCat

Answer 4

@AndrewTheCookie

Answer 5

@g

Answer 6

@anybody

Answer 7

What are the instructions for this problem?

Answer 8

To simplify it

Answer 9

Start by squaring each binomial.
Then combine like terms.

Answer 10

To square each binomial, you can use the formulas below, or if you prefer, use FOIL.
\((a + b)^2 = a^2 + 2ab + b^2\)
\((a - b)^2 = a^2 - 2ab + b^2\)

Answer 11

Wait a minute.

Answer 12

Wouldn't you first add the terms inside of the parenthesis.
So cos - cos = 0 and cos + cos = 2cos

Answer 13

Are you sure it's all cosines?

Answer 14

yes

Answer 15

If so, then it's much simpler.
On the left, cos theta - cos theta is zero.
On the right cos theta + cos theta = 2 cos theta.
Then square that.

Answer 16

4(cos)^2 theta

Answer 17

Correct.

Answer 18

Thanks!