How do you prove $secx+sin^2x+cos^2x=secx$ ?

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Answer 1 · 2015-12-20T06:35:47

This cannot be proven.

The first thing that should be recognized is the $sin^2x+cos^2x$ term.

This is the Pythagorean Identity: $sin^2x+cos^2x=1$

Thus, the equation can be rewritten:

$secx+(sin^2x+cos^2x)=secx$

$secx+1=secx$

$0!=1$

This equation has no solutions and is not a valid identity.

How do you prove secx+sin^2x+cos^2x=secxsecx+sin^2x+cos^2x=secx?