如图 求第二问
展开全部
f(x) =(sinx+cosx)^2
=1 + sin2x
f'(x)= 2cos2x
f'(x) =0
2cos2x = 0
2x = 2kπ + π/2 or 2kπ - π/2
x= kπ + π/4 or kπ - π/4
f''(x) = -4sin2x
f''(kπ - π/4) = -4sin(2kπ - π/2) = 4 >0 (min)
f(x)取最小值是变量x的集合 = { x| x=kπ - π/4 , k是整数 }
=1 + sin2x
f'(x)= 2cos2x
f'(x) =0
2cos2x = 0
2x = 2kπ + π/2 or 2kπ - π/2
x= kπ + π/4 or kπ - π/4
f''(x) = -4sin2x
f''(kπ - π/4) = -4sin(2kπ - π/2) = 4 >0 (min)
f(x)取最小值是变量x的集合 = { x| x=kπ - π/4 , k是整数 }
已赞过
已踩过<
评论
收起
你对这个回答的评价是?
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询