How do you simplify (1 - tan2(x)) /( 1 + tan2(x))?

1.	How do you simplify (1 - tan2(x)) /( 1 + tan2(x))?
Answer» (1 - tan²(x)) /(1 + tan²(x)) = cos 2x We’ll use trigonometric identity1 + tan²x = sec²xfor simplifying(1 - tan²(x)) /(1 + tan²(x))

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