You can put this solution on YOUR website! Given tanA=-2/3:A is in quadrant II find sin2A
hypotenuse of reference right triangle in quadrant II=√(2^2+3^2)=√13
sin2A=2sinAcosA=2*2/√13*(-3/√13)=-12/13
Check:
tanA=-2/3
A=146.31
2A=292.62˚
sin2A=sin(292.62˚)=-0.9230...
sin2A(as calculated)=-12/13=-0.9230..
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