SOLUTION: how to verify: tan^4 x + 2 tan^2 x + 1 = sec^4 x

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Question 626368: how to verify:
tan^4 x + 2 tan^2 x + 1 = sec^4 x
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
how to verify:
tan^4 x + 2 tan^2 x + 1 = sec^4 x
**
start with left side:
tan^4x+2tan^2x+1=(tan^2x+1)^2
identity:tan^2x=sec^2x-1
(tan^2x+1)^2
=(sec^2x-1+1)^2
=sec^4x
verified: left side=right side