trig
posted by stacey graham .
{tan^2x(1+cot^2x)} is equal to{1 divided by 1sin^2x}

tan^2x(1+cot^x)=1/(1sin^2x)
tan^2x(1+1/tan^2x)=1/cos^2x
tan^2x+(tan^x/tan^2x)=1/cos^2x
tan^2x+1=1/cos^2x
sin^2x/cos^2x+1=1/cos^2x
(sin^x+cos^2)/cos^2x=1/cos^2x
1/cos^2x=1/cos^2x