f(x)=a[2(cosx/2)^2+sinx]+b
(1)当a=1时,
f(x)=2(cosx/2)^2+sinx+b
=cosx+sinx+b+1
=√2sin(x+π/4)+b+1
单调增区间是[2kπ-3π/4,2kπ +π/4]
(2)当 a
f(x)=a[2(cosx/2)^2+sinx]+b
(1)当a=1时,
f(x)=2(cosx/2)^2+sinx+b
=cosx+sinx+b+1
=√2sin(x+π/4)+b+1
单调增区间是[2kπ-3π/4,2kπ +π/4]
(2)当 a