You can put this solution on YOUR website! tan(x)^3= tan(x)sec(x)^2-tan(x)
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tan(x)^3= tan(x)sec(x)^2-tan(x)
Starting with right-hand side
tan(x)sec(x)^2-tan(x)
identity: tan^2(x)+1=sec^2(x)
=tan(x)(tan^2(x)+1)-tan(x)
=tan^3(x)+tan(x)-tan(x)
=tan^3(x)
Verified: right-hand side=left-hand side