修改之后答案:
y = sqrt(x-2) + sqrt(4-x)
1.Differentiate:
dy/dx = 1/[2 * sqrt(x-2)] - 1/[2 * sqrt(4-x)]
2.Let dy/dx = 0 or undefined:
(a) When dy/dx = 0,
1/[2 * sqrt(x-2)] - 1/[2 * sqrt(x-4)] = 0
Therefore,x = 3
(b) When dy/dx is undefined:
x - 2 = 0 or x - 4 = 0
Therefore,x = 2 or x = 4
最后答案:
当x = 3时,y = 2为local maximum.
当x = 2或x = 4时,y = sqrt(2)为local minimum.
注:sqrt意思是平方根
还有 习惯了用英语做题 中文写不出来 过程lz凑合着看吧