The potential energy of the body with mass rn, constrained to move on a straight line is kx4, where k is a constant. The body moves from x1 at time to x2 at time t2. Which of the following quantities is an extremum for x Vs t curve corresponding to this motion?
1
\(\int _{t_1}^{t_2}\left(1/2mv^2-kx^4\right)dt\)
2
\(\int _{t_1}^{t_2}\left(1/2mv^2\right)dt\)
3
\(\int _{x_2}^{x_1}\left(1/2mv^2+kx^4\right)dx\)
4
\(\int _{x_2}^{x_1}(mxv)dx\)