Prove:
sin^3 X+cos^4 X=1
Here is what I have done so far:
Prrof:
sin^3x+cos^4x=1
sin^3x=1-cos^4x
sin^3x=(1-cos^2x)(1+cos^2x)
sin^3x=sin^2x(1+cos^2x)
sin^3x-[sin^2x(1+cos^2x)]=0
sin^2x[sinx-1(1+cos^2x)]=0
I do not know where to go from here or if I am on the right track... help.