查人人中国名人网眉姐续集在线阅读:高一 三角函数题
来源：百度文库 编辑：查人人中国名人网 时间：2024/05/08 13:06:12
若 ab不等于0
[asin(16∏5）+bcos(16∏5）]/[acos(16∏5）-bin(16∏5）]=tan(8∏/5)
则 b/a ＝？
[asin(16∏5）+bcos(16∏5）]/[acos(16∏5）-bin(16∏5）]=tan(8∏/5)
则 b/a ＝？
令tan(8∏/5)=x
sin(16∏/5)=2x/(1+x^2)
cos(16∏5）=(1-x^2)/(1+x^2)
[asin(16∏5）+bcos(16∏5）]/[acos(16∏5）-bin(16∏5）]
=[2ax+b(1-x^2)]/[a(1-x^2)-2bx]=x
2ax+b(1-x^2)=ax(1-x^2)-2bx^2
ax[x^2+1]=-b[1+x^2]
b/a=-x=-tan(8∏/5)