Question

http://calculustricks.com/lessons/trig-identities/

How do you simplify the first example?

Answer 1

which "first example" do you mean?

Answer 2

you there @Zarby ?

Answer 3

Hey there! Its half way down the page and the answer is,
= cos x

Answer 4

so you need an explanation to that?

Answer 5

ok do you get how they got to the 2nd step ?

Answer 6

Yes I do. I think you guess correctly that its the 2nd to 3rd step Im having a problem with :)

Answer 7

yep, you have to use pythagorean identity there
--> sin^2 +cos^2 = 1
therefore
--> sin^2 = 1-cos^2

Notice on the top there is a (1-cos^2) , they replaced it with a sin^2 because they are equivalent

Answer 8

Dang that took along time I finally got it. I just didn't see the math on subtracting cos^2 to the other side :P

Answer 9

THanks!