Find the value of k so that sum of the squares of roots of equation x2−8x+k=0 is 30.
Let the roots be a,b. ab=k,a+b=8 a2+b2=30 (a+b)2=64,a2+b2+2ab=64 30+2k=64,k=17
The positive value of k, for which both equations: x2 + kx + 64 =0 and x2 - 8x + k =0 have real roots is___________