F.4 TRIGONOMETRY M2!!
回答 (2)
2011-03-09 1:58 am
✔ 最佳答案
tanA + tanB= sinA/cosA + sinB/cosB
= (sinAcosB + cosAsinB)/(cosAcosB)
= sin(A + B)/(cosAcosB)
cotA + cotB
= cosA/sinA + cosB/sinB
= (cosAsinB + sinAcosB)/(sinAsinB)
= sin(A + B)/(sinAsinB)
(tanA + tanB)/(cotA + cotB)
= [sin(A + B)/(cosAcosB)]/[sin(A + B)/(sinAsinB)]
= tanAtanB
2011-03-09 6:09 am
(tan A + tan B)/(cot A + cot B)
= (tan A + tan B)/( 1/tan A + 1/tan B)
= (tan A + tan B)/[(tan A + tan B)/(tan A tan B)]
=tan A tan B.
= (tan A + tan B)/( 1/tan A + 1/tan B)
= (tan A + tan B)/[(tan A + tan B)/(tan A tan B)]
=tan A tan B.
收錄日期: 2021-04-26 14:04:43
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