- 已知cos(π2+φ)=-32且|φ|<π2,则tanφ=( )A.-3312B.33C.-3D.3
- 已知cos(π-α)=12,且α为第二象限的角,则sinα=______,tanα=______.
- 已知0<α<π2,且sinα=35(1)求sin2α+sin2αcos2α+cos2α的值;(2)求tan(α-54π)的值.
- 已知sin(π-α)=-2sin(π2+α),则sin2α等于( )A.-45B.-25C.25D.45
- 已知cosα=15,-π2<α<0,则cos(π2+α)tan(α+π)cos(-α)tanα的值为( )A.26B.-26C.-612D.612
- 已知cos(π2-ϕ)=32,且|ϕ|<π2,则tanφ=( )A.-33B.33C.-3D.3
- 已知αϵ(-π2,0),sinα=-35,则cos(π-α)=______.
- (Ⅰ)求值:sin690°•sin150°+cos930°•cos(-870°)+tan120°•tan1050°;(Ⅱ)已知角α的终边上有一点P(1,2),求4sinα-2cosα5...
- α∈(-π2,π2),sinα=-35,则cos(π-α)的值为( )A.-45B.45C.35D.-35
- 已知cos(π+x)=35,x∈(π,2π),则tanx等于( )A.-34B.-43C.34D.43
- 已知A、B、C三点的坐标分别为A(3,0)、B(3,0)、C(cosα,sinα)且AC•BC=-12.求:(Ⅰ)sinα+cosα的值;(Ⅱ)sin(π-4α)•c...
- 8sin870°•cos(-660°)•cot(-355°)•tan(-175°)的值是( )A.2B.-2C.12D.-12
- (1)化简1-2sin10°cos10°sin170°-1-sin2170°;(2)求值sin2120°+cos180°+tan45°-cos2(-330°)+sin(-210°)
- (1)已知tanα=2,求3sinα-2cosαsinα+3cosα+sin2α-3sinα•cosα的值.(2)已知角α终边上一点P(-3,1),求cos(π2+α)sin(-π-α)...
- 已知α是第四象限角,且cosα=35.(1)求tanα的值;(2)求sin(32π-α)+2cos(α+π2)sin(α-π)-3cos(2π-α)的值.