已知a∈R,函数f(X)=-2aSin(2x+π/6)+2a+b当x∈〔0,π/2〕,-5≤f(X)≤1. (1)求常数a,b的值
问题描述:
已知a∈R,函数f(X)=-2aSin(2x+π/6)+2a+b当x∈〔0,π/2〕,-5≤f(X)≤1. (1)求常数a,b的值
答
由x∈[0,π/2],可知2x+π/6∈[π/6,7π/6],Sin(2x+π/6)∈[-1/2,1],
(1)a>0时,有a+2a+b=1,-2a+2a+b=-5,解得a=2,b=-5
(2)a综上,a=2,b=-5或
a=-2,b=1