已知sin^2a+sin2acosa-cos2a=1 a(0,兀/2) 求sina,tana的值
人气：451 ℃ 时间：2020-04-24 00:26:14
解答
sin^2a+sin2acosa-cos2a=1 sin^2a+2sinacos^2a-1+2sin^2a=1 2sina(1-sin^2a)+3sin^2a=22sin^3a-3sin^2a-2sina+2=0(sina+1)(sina -2)(sina-1/2)=0∵a∈(0,兀/2) ∴sina=1/2tana=√3/3
推荐
- 已知sin^2a+sin2acosa-cos2a=1,a∈(0,π/2),求sina,tana的值(详细过程)
- 已知sin^2 2a+sin2acosa-cos2a=1,a E(0,π /2) 求sina tana
- 已知sin方2a+sin2acosa-cos2a=1,a∝(0,90),求sina,tana得值
- sin^2a+sin2acosa-2cosa=1,a属于（0,π/2）.求sina,tana.
- 已知sin2a^2+sin2acosa-cos2a＝1,a属于（0,π/2）,求sina,tana
- 20个少先队员收了160千克苹果，如果每筐装20千克，还差2个筐．原来有多少个筐？
- abcd,abcd的绝对值除以abcd得负1,求a分之a的绝对值+b分之b的绝对值+c分之c的绝对值+d分之d的绝对值的值
- last summer vacation,we_______many photos when we had a trip to dalian
猜你喜欢
