sin^4π/8-cos^4π/8=?

2个回答

cos^4π/8sin^4π/8等于
(cosπ/8+sinπ/8)（cos^3π/8-sin^3π/8）.
f(x)=1-2sin^2(x+π/8)+2sin(x+π/8)*cos(x+π/8)=cos(2x+π/4)+sin(
不用计算器,求(cos(π/8))^4+(cos(3π/8))^4+(cos(5π/8))^4+(cos(7π/8))^
已知sin(π8+α2)cos(π8+α2)＝14，α∈(π4，3π4)，cos(β−π4)＝35，β∈(π2，π)
fx=1-2sin^2(x+π/4)+2sin(x+π/8)cos(x+π/8)
化简:sin(a+5π)cos(-π/2-a)·cos(8π-a)/sin(a-3π)·sin(-a-4π)
sin²π/8 -cos²π/8
y=4sin(πx/8+π/4-π)怎样变成y=-4sin(πx/8+π/4）过程~
若8sin(π/4+α)sin(π/4-α)=1,则sin^4 a+cos^4 a=