The equation of one of the curves whose slope at any point is equal to y + 2x is

Solution of the differential equation xdy $$-$$ ydx = 0 represents a

If the displacement, velocity and acceleration of a particle at time t be x, v and f respectively, then which one is true?

The displacement x of a particle at time t is given by x = At² + Bt + C, where A, B, C are constants and v is velocity of a particle, then the value of 4Ax $$-$$ v² is