方程sinx+根号3cosx+a=0在(0,π/2)内有相异两根α、β,求α+β
问题描述:
方程sinx+根号3cosx+a=0在(0,π/2)内有相异两根α、β,求α+β
答
2sinx+√3cosx+a=02sin(x+π/3)=-asin(x+π/3)=-a/2x+π/3=2kπ+arcsin(-a)或x+π/3=2kπ+π-arcsin(-a/2)α=2kπ-arcsina/2-π/3 β=2kπ+π+arcsina/2-π/3α+β=4kπ+π/3∵α+β∈(0,π)∴α+β=π/3不...