There are proofs mathematically how we get kinematics formulae. But i can't understand the proof for kinetic energy equation. I know we can proof $KE$ equation from work energy theorem but what I learned was that we arrived from that change in $KE = W$. So I want proof for $KE = \frac{1}2 mv^2$ from other ways rather than work energy theorem.
Edit:
In kinematics acceleration makes sense when we say acceleration = rate of change of velocity . Which we can arrive mathematically as $a = \frac{v_f - v_i} t$ but i am curious to find how did we $KE = ??$ mathematically?