Trig Proof 4

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Taught by YourMathGal
  • Currently 4.0/5 Stars.
2391 views | 1 rating
Part of video series
Meets NCTM Standards:
Lesson Summary:

In this lesson, the instructor shows how to prove two trigonometric identities using fundamental and Pythagorean identities. The left-hand side of the identities are simplified first and then transformed using algebraic steps to match the right-hand side. The instructor emphasizes that there isn't just one way to prove a trigonometric identity as long as the algebraic steps and identities used are correct. Overall, this lesson shows that with a good understanding of the fundamental and Pythagorean identities, anyone can prove trigonometric identities.

Lesson Description:

Shows steps for proving (or verifying) Trigonometric Identities;

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Questions answered by this video:
  • How do you verify / prove trig identities?
  • What are some fundamental trig identities that you need to know to prove trig formulas?
  • What are the Pythagorean identities for trigonometry?
  • How do you prove that -1/(tan(x) - sec(x)) = (1 + sin(x))/cos(x)?
  • How do you prove that (1 -sin^2(x)*csc^2(x) + sin^2(x))/cos^2(x) = tan^2(x)?
  • Staff Review

    • Currently 4.0/5 Stars.
    Two more trig identities are verified in this lesson. Again, all steps involved in simplifying one side to make it look like the other side are shown and explained. This is a great tutorial for verifying trig identities. Make sure to check out all of the videos in this series if you need any help / practice proving trig identities.