已知函数f(x)=sin(2x+3分之π)+sin(2x-3分之π)+2cosx2-1 求函数f(X)在区间[-4分之π,四分之π]最大值,还有最小值
问题描述:
已知函数f(x)=sin(2x+3分之π)+sin(2x-3分之π)+2cosx2-1 求函数f(X)在区间[-4分之π,四分之π]最大值,
还有最小值
答
最大值: f(π/8) = (√2)sin(π/4 +π/4) =(√2)sin(π/2) = √2
最小值: f(-π/4) = (√2)sin(-π/2 +π/4) =(√2)sin(-π/4) = √2*(-√2/2) = -1