sin x+cos x=7/13 求tan x=?

求函数f(x)=sin ax+cos bx的周期为什么要TA/TB是有理数 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 已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x 已知sin(x)+3cos(x)=2,求sin(x)-cos(x)/sin(x)+cos(x)=? 已知sin[(π/4)-x)]=5/13,0<x<π/4.求cos2x/(cosπ/4+已知sin[(π/4)-x)]=5/13,0<x<π/4.求cos2x/[cos(π/4)+x] 已知0<β<π/2<α<π,cos[α-(β/2)]=-1/9,sin[(α/2)-β]=2/3 求cos(α+β) 已知α,β∈(0,π)且tan(α-β)=1/2,ta sin x+cos x=7/13 求tan x=? 已知:tan x=2 求:sin x+cos x/sin x-cos x=? 2sin^2x - 5sin x cos x=3 cos^2x,求X, f（x）=sin x +cos x +sin x * cos x ,求值域 求导数:(cos x)'=－sin x 求导数:(cos x)'=－sin x 求函数y=7-4sin(x)cos(x)+4cos^2(x)-4cos^4(x)值 cos x sin x=3,求cos x+sin x tan(x)=2求sin(x)cos(x)=? tan x=2,求 sin x * cos x=? f'(sin x)=1-cos x 求f''(x) 求f(x)=|sin x|+|cos x|的周期 sin（sin（sin（sin（x）=cos（cos（cos（cos（x）,X等于多少? cos x /sin x=