(cos2x+2sin(^2)x)/(cosx)=secx
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cos2x=cos^2x-sin^2x
numerator
cos^2x-sin^2x+2(1-cos^2x)
cos^2x-sin^2x+2-2cos^2x
-cos^2x-sin^2x+2
-1+2=1
denominator: cosx
numerator/deonominator
1/cosx=secx.
numerator
cos^2x-sin^2x+2(1-cos^2x)
cos^2x-sin^2x+2-2cos^2x
-cos^2x-sin^2x+2
-1+2=1
denominator: cosx
numerator/deonominator
1/cosx=secx.
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[(cos²x – sin²x) + 2sin²x]/cosx = (cos²x + sin²x)/cosx = 1/cosx = secx