SOLUTION: Let sin x = 1/3, with x in quadrant ll and let cos y = 3/4 with y in quadrant l. Find cos (x+y) and sin (x+y)
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Question 867175: Let sin x = 1/3, with x in quadrant ll and let cos y = 3/4 with y in quadrant l. Find cos (x+y) and sin (x+y) Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Let sin x = 1/3, with x in quadrant ll and let cos y = 3/4 with y in quadrant l. Find cos (x+y) and sin (x+y
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cos(x) = -sqrt(3^2-1)/3 = -sqrt(8)/3
sin(y) = sqrt(4^2-3^2)/4 = sqrt(7)/4
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cos(x+y) = cos(x)*cos(y) - sin(x)sin(y)
Substitute to get the cos(x+y) value
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sin(x+y) = sin(x)cos(y)+cos(x)sin(y)
Substitute gto get the sin(x+y) value
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Cheers,
Stan H.
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