Question 929749
using the double angle formula, find the exact value of sin(2x) given sinx=-(5/8) and tan x>0
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Reference angle x is in quadrant II where sin<0, cos<0
sinx=-5/8
cosx=&#8730;(1-sin^2(x))=&#8730;(1-(25/64))=&#8730;(39/64)=&#8730;39/8
sin(2x)=2sinxcosx=2*(-5/8)(&#8730;39)/8=-10&#8730;39/64