By completing the square, find in terms of the constant k k\,k the roots of the equation
x2+kx−7=0 x^2 + kx - 7 = 0 x2+kx−7=0Hence find the exact roots of the equation x2+8x−7=0x^2 + 8x - 7 = 0x2+8x−7=0
211 exam-style questions on Edexcel A Level Maths Quadratics, covering 2.1 Solving Quadratics, 2.2 Completing the Square, 2.3 Sketching Quadratic Graphs, 2.4 The Discriminant, and 2.5 Modelling with Quadratics. Each one has a worked solution and a mark scheme showing where the marks go.