Factorise then sketch

Questions where the function is given in expanded polynomial form and students must first factorise it before sketching the curve.

6 questions · Moderate -0.8

1.02j Manipulate polynomials: expanding, factorising, division, factor theorem1.02n Sketch curves: simple equations including polynomials
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Edexcel C1 2010 January Q9
13 marks Moderate -0.8
  1. (a) Factorise completely \(x ^ { 3 } - 4 x\) (b) Sketch the curve \(C\) with equation
$$y = x ^ { 3 } - 4 x ,$$ showing the coordinates of the points at which the curve meets the \(x\)-axis. The point \(A\) with \(x\)-coordinate - 1 and the point \(B\) with \(x\)-coordinate 3 lie on the curve \(C\).
(c) Find an equation of the line which passes through \(A\) and \(B\), giving your answer in the form \(y = m x + c\), where \(m\) and \(c\) are constants.
(d) Show that the length of \(A B\) is \(k \sqrt { } 10\), where \(k\) is a constant to be found.
Edexcel C1 2006 June Q9
8 marks Moderate -0.8
9. Given that \(\mathrm { f } ( x ) = \left( x ^ { 2 } - 6 x \right) ( x - 2 ) + 3 x\),
  1. express \(\mathrm { f } ( x )\) in the form \(x \left( a x ^ { 2 } + b x + c \right)\), where \(a\), \(b\) and \(c\) are constants.
  2. Hence factorise \(\mathrm { f } ( x )\) completely.
  3. Sketch the graph of \(y = \mathrm { f } ( x )\), showing the coordinates of each point at which the graph meets the axes.
Edexcel C1 2015 June Q8
10 marks Moderate -0.8
  1. (a) Factorise completely \(9 x - 4 x ^ { 3 }\) (b) Sketch the curve \(C\) with equation
$$y = 9 x - 4 x ^ { 3 }$$ Show on your sketch the coordinates at which the curve meets the \(x\)-axis. The points \(A\) and \(B\) lie on \(C\) and have \(x\) coordinates of - 2 and 1 respectively.
(c) Show that the length of \(A B\) is \(k \sqrt { } 10\) where \(k\) is a constant to be found.
Edexcel C1 Q14
5 marks Moderate -0.8
Given that \(f(x) = 15 - 7x - 2x^2\),
  1. find the coordinates of all points at which the graph of \(y = f(x)\) crosses the coordinate axes. [3]
  2. Sketch the graph of \(y = f(x)\). [2]
Edexcel C2 Q23
8 marks Moderate -0.8
Given that \(f(x) = 15 - 7x - 2x^2\),
  1. find the coordinates of all points at which the graph of \(y = f(x)\) crosses the coordinate axes. [3]
  2. Sketch the graph of \(y = f(x)\). [2]
  3. Calculate the coordinates of the stationary point of \(f(x)\). [3]
OCR C1 Q4
6 marks Moderate -0.8
$$\text{f}(x) = 4x - 3x^2 - x^3.$$
  1. Fully factorise \(4x - 3x^2 - x^3\). [3]
  2. Sketch the curve \(y = \text{f}(x)\), showing the coordinates of any points of intersection with the coordinate axes. [3]