The total relativistic energy of a particle of rest mass `m_0`, momentum p is
`E=sqrt(p^2c^2+m_0^2c^4)`
As de-broglie wavelength is same for electron and proton, i.e.,
`lambda_e=lambda_p or h/(p_e)=h/(p_p) so p_e=p_p`.
So minimum is same for them. so `p^2c^2` is same for them. But rest mass of proton is greater than that of electron, therefore, the total energy of a proton is greater than that of electron.