Trigonometryhard · Past Paper
If tan A = 1 and tan B = sqrt(3), find cos A cos B - sin A sin B.
A(1-sqrt(3))/(2*sqrt(2))
B(sqrt(3)-1)/(2*sqrt(2))
C1
D0
✓ Correct Answer: A — (1-sqrt(3))/(2*sqrt(2))
A=45, B=60. Expression is cos(A+B) = cos(105). Or (1/sqrt(2) * 1/2) - (1/sqrt(2) * sqrt(3)/2) = (1-sqrt(3))/(2*sqrt(2)).
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