# Pre calc

Find sin(2x), cos(2x), and tan(2x) from the given information.
sin(x) = 5/13, x in Quadrant I
sin(2x)?
cos(2x)?
tan(2x)?

I honeslty just need one good example of how to do these please show all work and finalize answer

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1. In QI, you have

sinx = 5/13
cosx = 12/13
tanx = 5/12

sin2x = 2sinx cosx = 2(5/13)(12/13) = 120/169

similarly using the other double-angle formulas.

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2. How did you know ot multiple it with cos

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3. because I studied the double-angle formulas, as you need to do!

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4. Ok I know that the equation for
cos(2x)=1-2sin^2(x) How would you plug that in? It will not work

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