Question

求解数学题！！急

Answer 1

第一题，如图所示

Answer 2

1、最大值是3
2x - π/4=2kπ - π/2
2x=2kπ - π/4
则x=kπ - π/8，(k∈Z)
最小值是-1
2x - π/4=2kπ + π/2
2x=2kπ + 3π/4
则x=kπ + 3π/8，(k∈Z)

追答

2、y=1 + 3cos[-(x - π/3)]
=1 + 3cos(x - π/3)
∴最大值是4
x - π/3=2kπ，则x=2kπ + π/3， (k∈Z)
最小值是-2
x - π/3=2kπ + π
则x=2kπ + 4π/3，(k∈Z)

3、由已知：2x + 2π/3=2kπ 或者2x + 2π/3=2kπ + π
∴2x=2kπ - 2π/3
x=kπ - π/3，(k∈Z)
或者2x=2kπ + π/3
x=kπ + π/6，(k∈Z)

4、y=-3cos[-(x - 5π/3)]=-3cos(x - 5π/3)
∵y=0
∴x - 5π/3=2kπ + π/2 或者 x - 5π/3=2kπ - π/2
则x=2kπ + 13π/6，(k∈Z)
或者x=2kπ + 7π/6，(k∈Z)

Answer 3

Answer 4

1