cosγ+sinγ=根号2*sin(γ+π/4) 怎么证明
sinα+sinβ=sinγ cosα+cosβ=cosγ 证明cos(α-γ)
请证明在三角形ABC中:cosα=(sin²γ+sin²β-sin²α )/2sinγ*s
在三角形ABC中,证明cosα=(sin²β+sin²γ-sin²α)/(2sinβ*si
sinα^2+sinβ^2+sinγ^2=1,那么cosαcosβcosγ最大值等于
cos2α/[sin(α-π/4)]=-根号2 /2,cosα+sinα=?
sin2α= 2sinα×cosα 怎么证明?
若sin^4a/sin^2b+cos^4a/cos^2b=1,证明sin^4b/sin^2a+cos^4b/cos^2a
试证明:1+2sinαcosα/cos平方α-sin平方α=tan(π/4-α)
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
sinα+cosα=根号2 求sin^4α-cos^4α
M=L(SinαSinβCosγ+CosαCosβ)在EXCEL中应该怎么写.
f(x)=2sinπ/4cosπ/4-2根号3sin^2π/4+根号3