Add or subtract? Simplify your answer if possible. Leave your answer in terms of sin theta and/or cos theta sin theta + 1/cos theta

sin theta + 1/cos theta

1 Answer
Jul 12, 2018

Let

E(theta) = sintheta+1/costheta

E(theta) = (sinthetacostheta+1)/costheta

This form is already in terms of sintheta and costheta, but let's continue anyway.

Recognizing that 1 is nothing more than sin^2theta+cos^2theta, we have

E(theta) = (sin^2theta+sinthetacostheta+cos^2theta)/costheta

We know that

a^3-b^3=(a-b)(a^2+ab+b^2) => a^2+ab+b^2=(a^3-b^3)/(a-b)

E(theta) = ((sin^3theta-cos^3theta)/(sintheta-costheta))/costheta=(sin^3theta-cos^3theta)/(sinthetacostheta-cos^2theta)

This is another possible answer.