A. c>b>a
B. b>a>c
C. a>b>c
D. a>c>b
已知α为锐角,cosα=(1+sqrt(5))/(4),则sin(α)/(2)=( )A. $\frac{3-\sqrt{5}}{8}$B. $\frac{-1
(0.7分)int sin 4xdx=dfrac (1)(4)int sin 4xdx=dfrac (1)(4)cos 4x+cA 正确B 错误89
已知sin(α-β)=(1)/(3),cosαsinβ=(1)/(6),则cos(2α+2β)=( )A. $\frac{7}{9}$B. $\frac{1}{
2 1 -1-|||-29.已知行列式 1 1 1 则 _(31)+(A)_(32)+(A)_(33)= __ _(31)+(A)_(32)-(A)_(33)=
若sin(α+β)+cos(α+β)=2sqrt(2)cos(α+(π)/(4))sinβ,则( )A. tan(α-β)=1B. tan(α+β)=1C. t
(2025新高考1卷)11、已知△ABC的面积为(1)/(4),若cos2A+cos2B+2sinC=2,cosAcosBSinC=(1)/(4),则()A.
已知a=(2)^(4)/(3),b=(4)^(2)/(5),c=(25)^(1)/(3),则( )A. b<a<cB. a<b<cC. b<c<aD. c<a<
已知 =ln (cos 4x),则 =ln (cos 4x)已知,则
[单选题]设两电流分别为i1=5sin(Πt+3Π/4)A,i2=4sin(Πt-Π/2)A,,则i1对i2的相位差为()A . 超前Π/4radB . 滞后3Π/4radC . 滞后Π/4radD . 超前3Π/4rad
求曲线 =t-sin t, =1-cos t =4sin dfrac (t)(2) 在点 (dfrac (pi )(2)-1,1,2sqrt (2)) 处的切线