求证sinx-cosx=根号2sin(x-π/4)

求证sinx-cosx=根号2sin(x-π/4) 求证 sin^2x/(sinx-cosx)-(sinx+cosx)/tan^2 x-1=sinx+cosx 求证sin^2x/sinx-cosx-(sinx+cosx)/(tan^2-1)=sinx+cosx谢谢GGJJ 为什么cosX+sinX=...为什么cosx+sinx=根号2 sin(x+π/4) sinx+cosx=根号2sin(?) cosx-sinx=根号2sinx,求证tanx=cosx-sinx/cosx+sinx谢谢了, （1）已知：(4sinx-2cosx)/(5cosx+3sinx)=6/11 求sinx乘以cosx的值（2）证明(cosx/1+sinx) - (sinx/1+cosx)=2（cosx-sinx)/1+sinx+cosx(3)求证:sin²x乘以tanx + cos²x乘以cotx+2sinx乘以cosx=tanx+cotx要用 sin²X+cos²X=1 证明:sin2x=2sinx*cosx为什么sin(x+x)=sinx*cosx+cosx*sinx? sinx+cosx/sinx-cosx=2 求sinx/cos^3x +cosx/sin^3x 求证:Sin^2 x / (sinx-cosx) - (sin x + cos x)/(ta求证:Sin^2 x / (sinx-cosx) - (sin x + cos x)/(tan^2-1) = sin x + cos x 1-2sinx cosx /COS^2X-SIN^2X =1-tanx/1+tanx 求证 若sinx+cosx=根号2,那么sin^4x+cos^4x的值是多少? 若sinx+cosx=根号2,那么sin^4x+cos^4x的值 若sinX+cosX=根号2,求sin^3X+cos^3X的值 f(x)=[2sin(x+π/3)+sinx]cosx-根号3sin2x,化简 求证：更号3cosX-sinX=2sin(派/3-x) 求证 sinx(cos^2 2x-sin^2 2x) + 2cosx cos2x sin2x= sin 5x 若(cos2x)/[sin(x-π/4)]=（-根号2）/2,则cosx+sinx=?