SOLUTION: Find the exact value of cos theta if the terminal side of theta in standard position contains the point (6,-8) a. -4/5 b. 3/5 c. 4/5 d. -3/5

Algebra ->  Trigonometry-basics -> SOLUTION: Find the exact value of cos theta if the terminal side of theta in standard position contains the point (6,-8) a. -4/5 b. 3/5 c. 4/5 d. -3/5      Log On


   

Question 340962: Find the exact value of cos theta if the terminal side of theta in standard position contains the point (6,-8)
a. -4/5
b. 3/5
c. 4/5
d. -3/5
Answer by jrfrunner(365) About Me  (Show Source):
You can put this solution on YOUR website!
given point (6,-8) means x=6, y=-8
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cos(theta)=x/r where r=sqrt%28x%5E2%2By%5E2%29
r=sqrt%286%5E2%2B%28-8%29%5E2%29=sqrt%28100%29=10
cos%28theta%29=x%2Fr=6%2F10=3%2F5