Check expression equivalent to

[aisha]

sec theta - sec theta (sin^2 theta)

=(1/cos theta) -(1/cos theta)(sin^2 theta)

sin^2 theta = 1-cos^2 theta

so after subbing this in I got

-cos^2 theta/cos theta

so an equivalent expression would be cos theta?

 

[Nylex]

Looks fine to me, although where you have -cos^2 θ/cos θ, there shouldn't be a -ve sign.

 

[dextercioby]

You should have factored \frac{1}{\cos \theta} and then it would have more clear...Yes,the final answer is \cos\theta.

Daniel.