On the trigonometry quiz I got back this morning, the final question was:
Verify the identity cos θ + (sin θ)(tan θ) = sec θ.
To earn full credit, I was supposed to transform the left side to the right side in the following steps:
cos θ + (sin θ)(sin θ/cos θ) =
cos θ + (sin2 θ/cos θ) =
(cos2 θ/cos) + (sin2 θ/cos θ) =
(cos2 θ + sin2 θ)/cos θ =
1/
(
Read more... )