2A=3,A=3/2
When x=0, 3cosφ = 2 and cosφ = 2/3.
T/2=π/w=2, w=π/2, that is, T=4.
Therefore: f (1)+f (2)+...+f (100)
=25(f( 1)+f(2)+f(3)+f(4))
= 25 * 3/2[cos(π/2+φ)+cos(π+φ)+cos(3π/2+φ)+cos(2π+φ)]
= 75/2 *(sinφ-cosφ+sinφ+cosφ)
=0