For any arbitrary motion in space, which of the following relations are true?
(a) `v_("average") = (1//2)(v(t_(1)) + v(t_(2)))`
(b) `v_("average") = [r(t_(2))-r(t_(1)]//(t_(2)-t_(1))`
(c) `v(t) = v(0) + at`
(d) `a_("average") = [v(t_(2))-v(t_(1))]//(t_(2)-t_(1))`
The average stands for average of the quantity over time interval `t_(1)` to `t_(2)`

Explanation

b) and e) are true, others are false because relations a),c) and d) hold only for uniform acceleration.