Simplify (1+cos2A+sin2A)/(1-cos2A+sin2A)?

1 Answer
Sep 18, 2016

Please see below.

Explanation:

(1+cos2A+sin2A)/(1-cos2A+sin2A)

Now sin2A=2sinAcosA and cos2A=2cos^2A-1=1-2sin^2A

Hence (1+cos2A+sin2A)/(1-cos2A+sin2A)

= (1+2cos^2A-1+2sinAcosA)/(1-(1-2sin^2A)+2sinAcosA)

= (1+2cos^2A-1+2sinAcosA)/(1-1+2sin^2A+2sinAcosA)

= (2cos^2A+2sinAcosA)/(2sin^2A+2sinAcosA)

= (2cosA(cosA+sinA))/(2sinA(sinA+cosA))

= (2cosA)/(2sinA)

= cotA