Question 622092
This question was just answered and I'm not sure if this is the same person or not. If so, please let me know where you're stuck and what part(s) do not make sense to you. Thanks.



cosx(tan^2x+1)=secx


cosx*tan^2x+cosx=secx


cosx*(sin^2x)/(cos^2x)+cosx=secx


(sin^2x)/(cosx)+cosx=secx


(sin^2x)/(cosx)+cosx*(cosx)/(cosx)=secx


(sin^2x)/(cosx)+(cos^2x)/(cosx)=secx


(sin^2x+cos^2x)/(cosx)=secx


1/(cosx)=secx


secx=secx


So this verifies the identity.