已知函数f(x)=2cos(π/2x+π/5),若实数x1,x2满足f(x1)-f(x2)=4,则(x1-x2)的绝对值的最小值是
问题描述:
已知函数f(x)=2cos(π/2x+π/5),若实数x1,x2满足f(x1)-f(x2)=4,则(x1-x2)的绝对值的最小值是
答
f(x)=2cos(π/2x+π/5)f(x1)-f(x2)=2cos(π/2x1+π/5)-2cos(π/2x2+π/5)= 4cos(π/2x1+π/5)-cos(π/2x2+π/5) = 2∵-1 ≤ cos(π/2x1+π/5) ≤ 1,-1 ≤ cos(π/2x2+π/5) ≤ 1∴ cos(π/2x1+π/5) = 1,cos(π/2x2+...