English: We do know that that alpha is algebraic over L right, because K is algebraic over L; that means, every element of K is algebraic over L. So, there exists a polynomial f in L X such that f alpha is 0, so there is a polynomial with coefficients in L which has alpha as a root.
Telugu: ఆ ఆల్ఫా L పైన బీజగణితమని మనకు తెలుసు, ఎందుకంటే K అనేది L పైన బీజగణితం; అంటే, K యొక్క ప్రతి మూలకం L పైన బీజగణితం.