化简sinx+sin(x+2π/3)+cos(x+5π/6)
题目
化简sinx+sin(x+2π/3)+cos(x+5π/6)
答案
=sinx+sin(x+2π/3)+sin(x+4π/3)
=sinx+sin(x+2π/3)+sin(x+2π/3)cos(2π/3)+sin(2π/3)cos(x+2π/3)
=sinx+sin(x+2π/3)-(1/2)sin(x+2π/3)+(√3/2)cos(x+2π/3)
=sinx+(1/2)sin(x+2π/3)+(√3/2)cos(x+2π/3)
=sinx+sin(x+2π/3+π/3)
=sinx+sin(x+π)
=sinx-sinx
=0
举一反三
已知函数f(x)=x,g(x)=alnx,a∈R.若曲线y=f(x)与曲线y=g(x)相交,且在交点处有相同的切线,求a的值和该切线方程.
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
最新试题
热门考点