The equation x2+(k+1)x+9=0x^2 + (k + 1)x + 9 = 0x2+(k+1)x+9=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.
63 exam-style questions on AQA A Level Maths 1.5.3 Quadratic functions. Each one has a worked solution and a mark scheme showing where the marks go.