在△ABC中,∠A=π4,tan(A+B)=7,AC=32. (Ⅰ)求sinC的值; (Ⅱ)求△ABC的面积.
在△ABC中,∠A=
,tan(A+B)=7,AC=3
.
(Ⅰ)求sinC的值;
(Ⅱ)求△ABC的面积.
π |
4 |
2 |
(Ⅰ)求sinC的值;
(Ⅱ)求△ABC的面积.
数学人气:813 ℃时间:2019-12-18 01:27:53
优质解答
(本小题满分13分) (I)在△ABC中,因为A+B+C=π…(1分)所以tanC=tan[π-(A+B)]=-tan(A+B)…(3分)因为tan(A+B)=7,所以tanC=-7…(4分)又tanC=sinCcosC=-7sin2C+cos2C=1解得|sinC|=7210…(5分)因为C...
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