早教吧作业答案频道 -->数学-->
证明sin(a+b)-sina=2sinb/2*cos(a+b/2)
题目详情
证明sin(a+b)-sina=2sinb/2*cos(a+b/2)
▼优质解答
答案和解析
证明:sin(a+b)-sina=sin[(a+b/2)+b/2]-sin[(a+b/2)-b/2]
=sin(a+b/2)*cos(b/2)+cos(a+b/2)*sin(b/2)-[sin(a+b/2)*cos(b/2)-cos(a+b/2)*sin(b/2)]
=2sin(b/2)*cos(a+b/2)
=sin(a+b/2)*cos(b/2)+cos(a+b/2)*sin(b/2)-[sin(a+b/2)*cos(b/2)-cos(a+b/2)*sin(b/2)]
=2sin(b/2)*cos(a+b/2)
看了 证明sin(a+b)-sin...的网友还看了以下:
设A是N阶实方阵(1)当N为奇数且AA^T=I及|A|=1时,证明|I-A|=0(零)(2)当M为 2020-05-13 …
设A为n阶矩阵,证明:R(A+I)+R(A-I)>=n已知R(A)=R(kA),k≠0;R(A+B 2020-05-14 …
求解线性代数设A是n阶矩阵,⑴若A满足矩阵方程A²-A+I=O,证明:A和I-A都可逆,并求解线性 2020-05-14 …
设A为n阶方阵,且A²+A=I证明A+2I可逆,I是单位矩阵 2020-06-12 …
1.利用公式C(a-ℓ)、S(a-ℓ)证明:(1)cos(3兀/2-a)=-sina(2)cos( 2020-07-13 …
已知:a*sina+b*cosa=c,a*cosa-b*sina=d,求证:a^2+b^2=c^2 2020-07-25 …
若a属于(135,225),则复数(cosa+sina)+(sina-cosa)i在复平面内所对应 2020-08-01 …
求一不等式证明.已知:x,y,z>=0,x+y+z=6.求证:(x+1/x)(y+1/y)(z+1/ 2020-10-31 …
求解数学题(二项式定理):设数列A0,A1,A2,...满足A0与A1不相等,A(i-1)+A(i+ 2020-11-01 …
三角函数1.求证:(1+sina+cosa+2sinacosa)/(1+sina+cosa)=sin 2021-01-23 …