Simplifying a Trigonometric Expression Using Trigonometric Identities (7.2.1)

Question 1

• Four basic trigonometric identities:
  
  • tan θ = (sin θ)/cos θ
  • cos^2 θ + sin^2 θ = 1 (the Pythagorean identity)
  • 1 + tan^2 θ = sec^2 θ
  • 1 + cot^2 θ = csc^2 θ

Answer 1

• Four basic trigonometric identities:
  
  • tan θ = (sin θ)/cos θ
  • cos^2 θ + sin^2 θ = 1 (the Pythagorean identity)
  • 1 + tan^2 θ = sec^2 θ
  • 1 + cot^2 θ = csc^2 θ

Question 2

• You can use trigonometric identities to help you simplify complicated trigonometric expressions.

Answer 2

• You can use trigonometric identities to help you simplify complicated trigonometric expressions.

Question 3

• Writing a trigonometric function in terms of just sines and cosines often makes it easier to simplify.

Answer 3

• Writing a trigonometric function in terms of just sines and cosines often makes it easier to simplify.