Perform the indicated operation and simplify.

Question

cos(t)-1/cos(t)

Answer 1

Here is a possibility:

"perform the indicated operation" would be subtraction which requires a common denominator.

So,

(cos²x - 1) / (cos x)

Simplify?

We can replace the numerator with -sin²x, because sin²x + cos²x = 1.

Now we have -sinxsinx/ cosx, but sinx/cosx = tanx.

So one possible simplification is -sinxtanx.