f(x)根号2sin(2x+5/2π)判断奇偶性

f(x)=√2sin(2x+5π/2)
=√2sin(2x+π/2)
=√2cos(2x)
f(-x)=√2cos(-2x)=√2cos(2x)
f(x)=f(-x)
偶函数.
2.
f(x)=lg[sinx+√（1+sin^2x)]
f(-x)=lg{sin(-x)+√[1+sin^2(-x)]}
=lg[-sinx+√(1+sin^2x)]
不奇不偶.