Question 1031119
sin(a)= 8/17, 0 < a < &#960;/2 and cos(B) = 3/5, 0 < B < &#960;/2,
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cos(a) = sqrt[17^2-8^2]/17 and sin(B) = sqrt[5^2-3^2]/5
 cos (a+b)= cos(a)*cos(b)-sin(a)sin(b)
= (15/17)(3/5) - (8/17)(4/5)
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= 45/85 - 32/85
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= 13/85
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Cheers,
Stan H.
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