Question 958397: Let (-4, -7) be a point on the terminal side of theta. Find the "exact values" of cos theta, sec theta, and cot theta.
Answer by lwsshak3(11628)   (Show Source):
You can put this solution on YOUR website! Let (-4, -7) be a point on the terminal side of theta. Find the "exact values" of cos theta, sec theta, and cot theta.
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use x for theta
reference angle x is in quadrant III, where sin<0, cos<0
hypotenuse of reference right triangle in quadrant III=√(4^2+7^2)=√(16+49)=√65
sinx=-7/√65
cosx=-4/√65=-(4√65)/65
secx=-√65/4
cotx=4/7
..
check: (w/calculator)
tanx=7/4
x≈240.2551˚
cosx≈cos(240.2551)≈-0.4961
exact value=-(4√65)/65≈-0.4961
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