The complete set of values of k, for which the quadratic equation x2−kx+k+2=0 has equal roots, consists of
2 + √2
2 ± √12
2 - √12
-2 - √12
Equal roots ⇒△=0 k2−4(k+2)=0 k2−4k−8=0 k=4¯¯¯¯+2√122 =2¯¯¯¯+√12