An Object Starts Moving At T 0 And Its Position Is Given By X Bt3 Ct2 At What

An object starts moving at t = 0, and its position is given by x = bt3 – Ct2. At what time (other than t = 0) is the instantaneous velocity equal to the average velocity? Assume b = 4.2 m/s3 and C = 6. m/s2.