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

How do you simplify the first example?

Question

http://calculustricks.com/lessons/trig-identities/

How do you simplify the first example?

lgbasallote · Answer

which "first example" do you mean?

lgbasallote · Answer

you there @Zarby ?

anonymous · Answer

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

lgbasallote · Answer

so you need an explanation to that?

dumbcow · Answer

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

anonymous · Answer

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

dumbcow · Answer

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

anonymous · Answer

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

anonymous · Answer

THanks!