1.化简sin25/12πsin11/6π-cos25/12πcos11/6π的值是
来源:学生作业帮 编辑:大师作文网作业帮 分类:数学作业 时间:2024/09/23 06:24:09
1.化简sin25/12πsin11/6π-cos25/12πcos11/6π的值是
2.已知sina=15/17,a是第二象限角,则cos[a-π/3]= cos[a+π/3]=
2.已知sina=15/17,a是第二象限角,则cos[a-π/3]= cos[a+π/3]=
sin(a+b)=sin(a)*cos(b)+cos(a)*sin(b)
sin(a-b)=sin(a)*cos(b)-cos(a)*sin(b)
cos(a+b)=cos(a)*cos(b)-sin(a)*sin(b)
cos(a-b)=cos(a)*cos(b)+sin(a)*sin(b)
那么
1,sin25/12πsin11/6π-cos25/12πcos11/6π
= - cos(25/12π+11/6π)
= - cos(47/12π)
2,sina=15/17 得到 cosa=√(1-(15/17)^2)=8/17
cos(a-π/3)
= cos(a)cos(π/3) + sind(a)sin(π/3)
=8/17 * 1/2 + 15/17 * √3/2
=4/17+15√3/34
再问: 2.cosa是第二象限的角呢
再答: 哦。忘记了,那就前面加个负号,cosa=-8/17, 再代入式中。 -4/17+15√3/34
sin(a-b)=sin(a)*cos(b)-cos(a)*sin(b)
cos(a+b)=cos(a)*cos(b)-sin(a)*sin(b)
cos(a-b)=cos(a)*cos(b)+sin(a)*sin(b)
那么
1,sin25/12πsin11/6π-cos25/12πcos11/6π
= - cos(25/12π+11/6π)
= - cos(47/12π)
2,sina=15/17 得到 cosa=√(1-(15/17)^2)=8/17
cos(a-π/3)
= cos(a)cos(π/3) + sind(a)sin(π/3)
=8/17 * 1/2 + 15/17 * √3/2
=4/17+15√3/34
再问: 2.cosa是第二象限的角呢
再答: 哦。忘记了,那就前面加个负号,cosa=-8/17, 再代入式中。 -4/17+15√3/34
1.化简sin25/12πsin11/6π-cos25/12πcos11/6π的值是
sin11/π*sin11/3π*sin11/5π分之sin11/10π*sin11/8π*sin11/6π 等于多少
计算:sin25π/6+cos25π/4+tan(-25π/4)+sin(-26π/3)
求值sin25π/6+cos25π/3+tan(-25π/4)+sin(-7π/3)×cos(-13π/6)-sin(-
sin25π6
sin25π/4+cos25π/3+tan(-25π/4)=
sin25/6pai+cos25/3pai+tan(-25/4pai)
三角函数的计算题目cos25/3*π=tan(-15/4*π)
1sin3分之4π乘以6分之cos25π乘以tan-4分之3π=
sin25π/6+cos10π/3+tan(-25π/4)+sin(-7π/3)×cos(-13π/6)=
cos25πtdt (0~π/4)的微积分怎么求?
cos25π/3等于?请告诉我具体的方法,O(∩_∩)O谢谢