# Math

if sec theta = -13/5 on the interval(90,180), find the exact value of sin 2 theta

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1. if secTheta=-13/5, then cosTheta=-5/13
cos^2 + sin^2=1
sin^2=1-25/169=144/169

sin(2Theta)=2sinTheta*cosTheta=2(12/13)(-5/13)= you do it.
check my thinking

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bobpursley

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