If A and B are complementary angles, find the value of
cos A cos B + sin A sind B
______________________
sin A sin B
Please help to solve S2 math.
2008-05-07 9:19 am
回答 (2)
2008-05-07 5:20 pm
✔ 最佳答案
A and B are complementary anglesso A+B = 90
and use the formula sin(90-A) = cosA
(cos A cos B + sin A sind B ) / (sin A sin B)
= (cos A cos (90-A) + sinA sin (90-A) ) / (sin A sin (90-A))
= (cos A sin A + sinA cos A ) / (sin A cos A)
= 2(cos A sin A ) / (sin A cos A)
=2
2008-05-12 11:28 pm
cosAcosB+sinAsinB =cos (A-B) 囉 = ="
收錄日期: 2021-04-13 15:31:32
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