Further Pure Mathematics 4PM1 / Sketching Polynomials / 1.141.14: Expanding and Solving a Cubic Equation4PM1/1/January/2019 — Question 3 · 5 marksMark as done · Save for laterf(x)=(2x+1)(x2+5x−3).f(x)=(2x+1)(x^2+5x-3).f(x)=(2x+1)(x2+5x−3).(a) Show thatf(x)=2x3+11x2−x−3.f(x)=2x^3+11x^2-x-3.f(x)=2x3+11x2−x−3.(2)(b) Hence use algebra to solve the equation2x3+11x2−x−3=0.2x^3+11x^2-x-3=0.2x3+11x2−x−3=0.Give your roots to 3 decimal places where appropriate.(3)▸ Mark scheme← 1.11: 4PM1/1/June/2019 — Question 11.15: 4PM1/1/January/2019 — Question 8 →
