Question

4. [0.5/1 Points] Use an Addition or Subtraction Formula to write the expression as a trigonometric function of one number. $\cos(\frac{4\pi}{5})\cos(\frac{7\pi}{15}) + \sin(\frac{4\pi}{5})\sin(\frac{7\pi}{15})$ Find its exact value. $\frac{1}{2}$

          4. [0.5/1 Points]
Use an Addition or Subtraction Formula to write the expression as a trigonometric function of one number.
$\cos(\frac{4\pi}{5})\cos(\frac{7\pi}{15}) + \sin(\frac{4\pi}{5})\sin(\frac{7\pi}{15})$
Find its exact value.
$\frac{1}{2}$

4. [0.5/1 Points]
Use an Addition or Subtraction Formula to write the expression as a trigonometric function of one number.
cos((4π)/(5))cos((7π)/(15)) + sin((4π)/(5))sin((7π)/(15))
Find its exact value.
(1)/(2)

Added by Kathy W.

Precalculus with Limits

Ron Larson 2nd Edition

Instant Answer

Solved by Expert Lauren Shelton

04/08/2024

Step 1

Step 1: The given expression is in the form of the cosine addition formula: $$cos(A-B)=cos(A)cos(B)+sin(A)sin(B)$$ Show more…

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4. [0.5/1 Points] DETAILS MY NOTES SPRECALC8 7.2.504.XP. PREVIOUS ANSWERS ASK YOUR TEACHER PRAC Use an Addition or Subtraction Formula to write the expression as a trigonometric function of one number. $$cos(\frac{4\pi}{5})cos(\frac{7\pi}{15})+sin(\frac{4\pi}{5})sin(\frac{7\pi}{15})$$ Find its exact value. $$\frac{1}{2}$$ Need Help? Read It Watch It Submit Answer