cos(- 19/4 π)=?
cos(- 19/4 π)=?
cos(-19/6π)=?
cos(π/32)*cos(π/16)*cos(π/8)=
cos(-19π/4)的值
cos(-19/6π)
已知cos(π4
已知(sinα-cosα)/(sinα+cosα)=1/3,则cos^4(π/3+α)-cos^4(π/6-α)的值为
f(x)=4cos(wx-π/6)sinwx-cos(2wx+π) 化简
f(x)=4cos(wx-π/6)sinwx-cos(2wx+π/3)请化简
已知cosa=1/4,求sin(2π+a)cos(-π+a)/cos(-a)tana
1)求证cotαcosα/cotα-cosα=tan(α/2+π/4)
f(x)=4cos(wx-π/6)sinwx-cos(2wx+x) 求值域