A particle is in a QM state ψ that is not an eigenfunction of the Energy operator H but is a superposition of eigenfunctions of the Energy operator ψ1 and ψ2 that have eigenvalues E1 and E2 so that ψ can be written as ψ = c1ψ 1 + c2ψ 2 where ψ 1 and ψ 2 are orthonormal, and c1 and c2 are expansion coefficients. What is the probability of getting E1 as athe energy value for this QM state?
any help would be appreciated