高一数学人教版必修4习题3.1A组(13)-(19)

问题描述:

高一数学人教版必修4习题3.1A组(13)-(19)
高一数学人教版必修4习题3.1A组(13)~(19)

(1)6√5sin(x+6/π)
(2)√3sin(3/π-x)
(3)2sin(x/2+π/6)
(4)√2/2sin(7π/12-x)
(5)√2/2
(6)1/2
(7)sin(α+γ)
8)—cos(α-γ)
(9)—√3
10)tan(β-α)
(14:sin2α=0.96 cos2α=-0.28
15:sin2ф=2√2/3 cos2ф=-1/3 tan2ф=-2√2
16:由题意设:sinB=sinC=5/13 ,切0°<B<90°,所以cosB=12/13.所以sinA=sin(180°-2B)=sin2B=120/169,同样:cosA=-119/169,tanA=-120/119
17:先求tan2β=3/4,然后可得tan(α+2β)=1
18:由已知得cosα=1/3,于是又sinα=-2√2/3,sin2α=-4√2/9,cos2α=-7/9
19:(1)1+sin2α (2)cos2 θ (3)1/4sin4x (4)tan2 θ