解答(1)cos(-11π/6) (2)tan9π/4 (3)sin1140°
tan9π/8
比较下列各组数的大小(1)tan2π/5与tan3π/5(2)tan2与tan9(3)log1/2tan70°与log1
数学题在线解答已知0<α<π/2<β<π,cos(β-π/4π)=1/3,sin(α+β)=4/5.求cos(α+π/4
已知tana=1/2,求sin^2a-3sinacosa+4cos^2a解答,
cos^2(π/3-a)+cos^2(π/6+a)
已知(sinα-cosα)/(sinα+cosα)=1/3,则cos^4(π/3+α)-cos^4(π/6-α)的值为
【紧急求助】计算:cosα+cos(2π/3 +α)+cos(4π/3 +α)
sin(π+π/6)-cos(π+π/4)cos(-π/2)+1
高一三角函数题目化简cos[(3k+1)/3*π+α)+cos[(3k-1)/3*π-α],其中k∈Z 麻烦大家详细解答
解答DSP试题有一调幅信号,x(t)=[1+cos(2π×100t)]cos(2π×600t)用DFT做频谱分析,要求能
f(x)=4cos(wx-π/6)sinwx-cos(2wx+π/3)请化简
已知α∈(π/2,π),且4sinα=-3cosα 求cos(α+π/4)/sin2α的值 希望老师能详细解答