J Jessika New member Joined Feb 20, 2014 Messages 1 Feb 20, 2014 #1 Using basic identities to simplify the expression. How to simplify cosx-cos^3x I know the answer is cos(x)sin^2(x) But I just don't know how to get to there? Last edited by a moderator: Feb 21, 2014
Using basic identities to simplify the expression. How to simplify cosx-cos^3x I know the answer is cos(x)sin^2(x) But I just don't know how to get to there?
W wjm11 Senior Member Joined Nov 13, 2004 Messages 1,417 Feb 20, 2014 #2 Jessika said: Using basic identities to simplify the expression. How to simplify cosx-cos^3x I know the answer is cos(x)sin^2(x) But I just don't know how to get to there? Click to expand... Factor out a cosx and use one of the Pythagorean trig identities. They are easily looked up.
Jessika said: Using basic identities to simplify the expression. How to simplify cosx-cos^3x I know the answer is cos(x)sin^2(x) But I just don't know how to get to there? Click to expand... Factor out a cosx and use one of the Pythagorean trig identities. They are easily looked up.
