f(x)=x3−(k+2)x2+(2k+5)x−5kf(x)=x^3-(k+2)x^2+(2k+5)x-5kf(x)=x3−(k+2)x2+(2k+5)x−5k, where k k\,k is a real constant.
Use the factor theorem to show that (x−k)(x - k)(x−k) is a factor of f(x)f(x)f(x).
Show that f(x)=0f(x) = 0f(x)=0 only has one real root, giving your answer in terms of kkk.
257 exam-style questions on Edexcel A Level Maths Algebraic Methods, covering 7.1 Algebraic Fractions, 7.2 Dividing Polynomials, 7.3 The Factor Theorem, 7.4 Mathematical Proof, and 7.5 Methods of Proof. Each one has a worked solution and a mark scheme showing where the marks go.