Sections:

Trigonometric Identities and Equations, Page 12

Examples (continued)

Example 2:

Simplify the expression cot θ tan θ + sin θ sec θ .

Procedure:

  1. Check to see if there are any trigonometric identities that can be replaced.
  2. Rewrite everything in terms of sine and cosine.
  3. Simplify.

Solution:

cot θ = cosθ/sinθ, tan θ = sinθ/cosθ. sec θ = 1/cosθ


cosθ/sinθ * sinθ/cosθ + sin θ * 1/cosθ = 1 + sinθ/cosθ = 1 + tan θ