A particle moves in the xy-plane with a constant acceleration g in the negative y-direction. Its equation of motion is y = ax - bx2, where a and b are constants. Which of the following are correct?

A particle moves in the xy-plane with a constant acceleration g in the negative y-direction. Its equation of motion is y = ax - bx2, where a and b are constant. Then the correct statements are(i)  The x-component of its velocity is constant.(ii)  At the origin, the y-component of its velocity is ag/2b.(iii)  At the origin, its velocity makes an angle tan−1a with the x-axis.(iv)  The particle moves exactly like a projectile.