Which of the following equations apply to the horizontal motion (x-direction) of an ideal projectile with g = 9.8 m/s² (neglecting effects due to the air)? (Mark all that apply.)
a) x = v₀t
b) x = v₀t + (1/2)gt²
c) x = v₀cosθt
d) x = v₀t - (1/2)gt²