Trig Proof 5

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Taught by YourMathGal
  • Currently 4.0/5 Stars.
1293 views | 1 rating
Part of video series
Meets NCTM Standards:
Lesson Description:

We verify a Trig identity by using the basic identities and the identity for the cosine of a sum or difference. We prove that (cos(x+y))/(cosx * cosy) = 1 - tanx * tany using a trig proof.

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Questions answered by this video:
  • How do you verify trig identities?
  • How can you prove that (cos(x+y))/(cosx * cosy) = 1 - tanx * tany
  • How do you make one side of the equal sign equal the other side in a trig proof?
  • Staff Review

    • Currently 4.0/5 Stars.
    This lesson shows how to do a trig proof by making one side of the equal sign look like the other side. All steps of the proof are shown in a way just as you would be expected to complete such a proof. This is a great trig proof tutorial.