How do you simplify sqrt(1+tan^2x)1+tan2x?

1 Answer
Jan 13, 2017

sqrt(1+tan^2 x) = abs(sec x)1+tan2x=|secx|

Explanation:

Using:

cos^2 x + sin^2 x = 1cos2x+sin2x=1

tan x = sin x / cos xtanx=sinxcosx

sec x = 1/cos xsecx=1cosx

we find:

sqrt(1+tan^2 x) = sqrt(1+(sin^2 x)/(cos^2 x))1+tan2x=1+sin2xcos2x

color(white)(sqrt(1+tan^2 x)) = sqrt((cos^2 x)/(cos^2 x)+(sin^2 x)/(cos^2 x))1+tan2x=cos2xcos2x+sin2xcos2x

color(white)(sqrt(1+tan^2 x)) = sqrt((cos^2 x+sin^2 x)/(cos^2 x))1+tan2x=cos2x+sin2xcos2x

color(white)(sqrt(1+tan^2 x)) = sqrt(1/(cos^2 x))1+tan2x=1cos2x

color(white)(sqrt(1+tan^2 x)) = sqrt(sec^2 x)1+tan2x=sec2x

color(white)(sqrt(1+tan^2 x)) = abs(sec x)1+tan2x=|secx|