1/cos(x) - tan(x) = 3 求sin(x)
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
已知tan x=-3/4,求sin x ,cos x ,cot x 的值.
证明(1-2sin x cos x )/(cos^2x-sin^2x)=(1-tan x)/(1+tan x)
证明1-tan^2x/1+tan^2x=cos^2x-sin^2x
求极限x趋于0时(1-cos(x/2))x / (tan x-sin x)
tan x=1.5 求sin x 和.cos x
证明:(1 + tan x) / (sin x + cos x) = 1 / cos x
证明 (tan xsin x)/(tan x-sin x)-(1+cos x)/sin x
已知1+tan/1-tan=3+2根号2,求(sin^2x+根号2sinxcosx-cos^2)/(sin^2+2cos
已知Sin x=3/5且x是第二象限角求cos x tan x
若tanx=2,求:sin(tt/2+x)*cos(tt/2-x)*tan(-x+3tt)/sin(7tt-x)*tan
已知tan(π/4-x)=-1/3,求 sin^2(x+π/4)/2cos^2+sin2x