Question

求解答数学题！要有步骤！

求解答

Answer 1

f(x)= -x^3+3x
f'(x) =-3x^2+3 =0
x= 1 or -1，在【-1,1】单调递增，其他单调递减
f''(x) = -6x
f''(1) =-6 <0 取得最大值
f''(-1) =6 >0 (取得最小值
max f(x) = f(1) = 2
min f(x) = f(-1) = -4

Answer 2

f(x)= -x^3+3x
f'(x) =-3x^2+3 =0
x= 1 or -1
f''(x) = -6x
f''(1) =-6 <0 (max)
f''(-1) =6 >0 ( min)
max f(x) = f(1) = 2
min f(x) = f(-1) = -4