The equation x2+kx+2=0x^2 + kx + 2 = 0x2+kx+2=0 where k k\,k is a constant, has no real roots.
Find the set of possible values for kkk, giving your answer in set notation.
8 exam-style questions on OCR A Level Maths 1.2.4 Quadratic functions. Each one has a worked solution and a mark scheme showing where the marks go.