Question 308497
Given: cscx=5/3; secx<0
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csc = 1/sin
sin(x) = +3/5 --> Quad 1 or 2
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sec<0 --> Quad 2 or 3
--> Quadrant 2
cos(x) = -4/5
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Find exact values:
a. cos (2x)
= 1 - 2sin^2(x)
= 1 - 2*(3/5)^2 = 1- 18/25
= 7/25
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c. sin (2x)
= 2 sin(x) cos(x)
= 2(3/5)*(-4/5)
= -24/25
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b. tan (2x) = sin(2x)/cos(2x)
= -24/7