1.由题意sinx+cosx=0==>√2sin(x+π/4)=0∵-π/22.由题意y=√[(sinx+1)^2+(cosx+1)^2]=√[3+2(sinx+cosx)] =√[3+2√2sin(x+π/4)]Y’=[2√2cos(x+π/4)]/{2√[3+2√2sin(x+π/4)]}令2√2cos(x+π/4)＝0，x1=2kπ+π/4,x2=2kπ+5π/4当2kπ+π/4当2kπ+5π/40,函数Y单调增；函数图像的对称轴方程为：x1=2kπ+π/4,x2=2kπ+5π/4
