What is sectheta+costheta in terms of sintheta?

1 Answer
Dec 12, 2015

Recall:
1. sectheta=1/costheta

To rewrite the expression in terms of sintheta, use the above reciprocal identity to simplify the expression:

sectheta+costheta

=1/costheta+costheta

=(1+costheta(costheta))/costheta

=(1+cos^2theta)/costheta

=(1+(1-sin^2theta))/costheta lArr cos^2theta=1-sin^2theta

=(2-sin^2theta)/costheta