Compute using Trig Identities 5

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Taught by YourMathGal
  • Currently 4.0/5 Stars.
1386 views | 1 rating
Part of video series
Meets NCTM Standards:
Lesson Summary:

In this lesson, Julie Harland uses trigonometric identities to solve problems involving tangent, sine, cosine, and cotangent. Through the use of these identities, she is able to find the exact values of these functions for given angles. While some of the problems are more involved, Harland stresses the importance of knowing these identities to solve them quickly and efficiently.

Lesson Description:

Using Trig Identities to make computations.

More free YouTube videos by Julie Harland are organized at http://yourmathgal.com

Questions answered by this video:
  • If cosx = -3/5 and siny = 12/13, with both x and y between 90 and 180 degrees, how do you find tan(x - y)?
  • If you know cosx and siny, how would you find tan(x - y)?
  • If you know cosx and siny, how would you find sin(2x)?
  • If you know cosx and siny, how would you find cos(x+y)?
  • If you know cosx and siny, how would you find cot(pi/2 - x)?
  • If you know cosx and siny, how would you find cos(-x)?
  • Staff Review

    • Currently 4.0/5 Stars.
    This lesson shows how to compute several different trig expressions if you know the value of cos(x) and sin(y). All steps involved in making the computations are shown and explained very clearly in this lesson. Check out the next lessons in this series for more example problems.