求下列各三角函数值
求下列各三角函数值 -
;tan(-31/4π)=-tan(31/4π)=-tan(8π-1/4π)=-tan(-1/4π)=tan(1/4π)=1
(1)解法1:sin()=-sin16 =-sin(4π+) =-sin=-sinπ+=sin=. 解法2:sin()=sin(-6π+) =sin=sin(π-)=sin=. (2)cos(-945°)=cos945°=cos(2×360°+225°) =cos225°=cos(180°+45°)=-cos45°=.
;tan(-31/4π)=-tan(31/4π)=-tan(8π-1/4π)=-tan(-1/4π)=tan(1/4π)=1
(1)解法1:sin()=-sin16 =-sin(4π+) =-sin=-sinπ+=sin=. 解法2:sin()=sin(-6π+) =sin=sin(π-)=sin=. (2)cos(-945°)=cos945°=cos(2×360°+225°) =cos225°=cos(180°+45°)=-cos45°=.
4、sin900°=sin(720 °+180 °)=sin180 °=0
解:1、sin750° =sin(360×2+30)° =sin30° =0.5 2、cos 22π/3 =cos(6π+4π/3)=cos 4π/3 =-0.5 3、tan(-7π/4)=tan(-2π+π/4)=tan π/4 =1 4、sin900° =sin(360×2+180)° =sin180° =0 望采纳,谢谢!
1、求下列各三角函数值 -
①sin750°=sin(2×360º+30º)=sin30º=1/2 ②cos22派/3=cos(3×2π+4π/3)=cos(4π/3)=-cos(π/3)=-1/2 ③tan(7派/4=tan(2π-π/4)=tan(-π/4)=-tan(π/4)=负的二分之根号二④sin900°=sin(2×360º+180º)=sin180º=0 有帮助请点赞。
-17π/6=-18π/6 + π/6 =-3π +π/6 因此:tan(-17π/6)=tan(-3π +π/6)=tan(-π+π/6)=tan(-5π/6)=-tan(5π/6)=-tan(π - π/6)=tan(π/6)=√3/3 -31π/4=-32π/4+π/4=-8π+π/4 因此:tan(-8π+π/4)=tanπ/4=1 后面会介绍。
求下列各三角函数的值 -
1.sin240°=sin(180°+60°)=-sin60°=-√3/2 2.cos300°=cos(360°-60°)=cos60°=1/2 3.tan150°=tan(180°-30°)=-tan30°=-√3/3 4.sin405°=sin(360°+45°)=sin45°=√2/2 5.cos(-120°)=cos120°=cos(180°-60°)=-cos60°=-1/2 6.tan(-60°)=-tan60等我继续说。
解⑴sin105°=sin﹙60°+45°﹚=sin60°cos45°+cos60°sin45° =﹙√3/2﹚﹙√2/2﹚+﹙1/2﹚﹙√2/2﹚=﹙√6/4﹚+﹙√2/4﹚=﹙√ 6+√2﹚/4 ⑵cos165°=cos﹙180°-15°﹚=-cos15° =-cos﹙45°-30°﹚=-﹙cos45°cos30°+sin45°sin30°﹚=后面会介绍。
求下列各三角函数值:(1)cos(-11π/6) (2)tan9π/4 (3)sin1140°_百度知...
解·1 cos(-11π/6) =cos(2π-11π/6) =cos(π/6) =√3/2 2 tan9π/4=tan(2π+π/4)tanπ/4=1 3,sin1140°=sin(3×360°+60°)sin60°=√3/2.
1、tan225°=tan(180°+45°)=tan45°=1 2、sin660°=sin(720°-60°)=-sin60°=-√3/2 3、cos495°=cos(360°+135°)=cos(90°+45°)=-sin45°=-√2/2