i cant quite seem to get this.. thanks for the help. x Prove the following indenty. You may assume the formulas for sun2x and cos2x. cos3x = 4cos(^3)x - 3cosx
Follow Math Help Forum on Facebook and Google+
Originally Posted by pop_91 i cant quite seem to get this.. thanks for the help. x Prove the following indenty. You may assume the formulas for sun2x and cos2x. cos3x = 4cos(^3)x - 3cosx cos (3x)=cos(x+2x) use identity cos (A+B)=cos B cos B-sin A sin B cos 2A an sin 2A.
i've done that and sub in 1-cos^2x but i dont get the correct answer
Originally Posted by pop_91 i've done that and sub in 1-cos^2x but i dont get the correct answer put
ive got it now! thanks
View Tag Cloud