化简cos(π/12)*cos(5π/12)
化简cos(π/12)*cos(5π/12)
计算cos(a+5π/12)cos(a+π/6)+cos(π/12-a)cos(π/3-a)
若cos(5π12
已知cos(5π12
帮我解,证明恒等式(cos平方5π/12)+(cos平方π/12)+(cos5π/12)(cosπ/12)=5/4
数学,证明恒等式(cos平方5π/12)+(cos平方π/12)+(cos5π/12)(cosπ/12)=5/4.
化简cos(π/12-α)-根号3cos(5π/12+α)
化简sin(25π/12)cos(11π/6)-cos(11π/12)sin(5π/6)的值是
化简sin(2π+a)cos(π-a)cos(π/2-a)cos(7π/2-a)/cos(π-a)sin(3π-a)si
cos^2(π/6)
【1】化简:sin(a-5π)/cos(3π-a)×cos(π/2-a)/sin(a-3π)×cos(8π-a)/sin
已知α=7/12π,那么cosα√(1-sinα)/(1+sinα)+sinα√(1-cosα)/(1-cosα)=