SOLUTION: Find the exact value of sin 2u, cos 2u, and tan 2u given that the terminal sideof angle u goes through the point (1,2)

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Question 875295: Find the exact value of sin 2u, cos 2u, and tan 2u given that the terminal sideof angle u goes through the point (1,2)

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Find the exact value of sin 2u, cos 2u, and tan 2u given that the terminal sideof angle u goes through the point (1,2)
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you are working with a reference right triangle in quadrant I, in which:
sin u=2/√5
cos u=1/√5
tan u=sin/cos=2/1=2
..
sin 2u=2sinucosu=2*2/√5*1/√5=4/5
cos 2u=cos^2u-sin^2u=1/5-4/5=-3/5
tan 2u=sin 2u/cos 2u=-4/3