i have been given that vector r = bt^2i + ct^3j where b and c are positive constants, and i need to know when the velocity vector will make an angle of 45 degrees. i have been trying to figure it out and am just confused. i have taken the derivative of vec r, because i know that it becomes velocity but i dont know what to do from there. i cannot figure out the components of what makes up the velocity vector. i feel like i am going in circles. please someone help!!