数学三角函数计算题化简:1:sin58度cos37度-cos58度sin37度2;3乘以根号15乘以sinx + 3乘以根号5乘以cosx等于?3:sin347度乘以cos148度+sin77度乘以cos58度等于?4;sin164度乘以sin224度+sin254度乘以sin314度等于?5; cos(a-b)乘以cos(b-r) - sin(a-b)乘以sin(b-r)
2019-04-13
数学三角函数计算题
化简:1:sin58度cos37度-cos58度sin37度
2;3乘以根号15乘以sinx + 3乘以根号5乘以cosx等于?
3:sin347度乘以cos148度+sin77度乘以cos58度等于?
4;sin164度乘以sin224度+sin254度乘以sin314度等于?
5; cos(a-b)乘以cos(b-r) - sin(a-b)乘以sin(b-r)
优质解答
1=sin(58°-37°)=sin21°
2=6乘以根号5乘以sin(x+30°)
3=sin13°*cos32°+cos13°*sin32°=sin45°=√2/2
4= -sin16°*sin44°+cos16°*cos44°=cos60°=1/2
1=sin(58°-37°)=sin21°
2=6乘以根号5乘以sin(x+30°)
3=sin13°*cos32°+cos13°*sin32°=sin45°=√2/2
4= -sin16°*sin44°+cos16°*cos44°=cos60°=1/2