Verify factor then simplify rational expression

Questions that verify a factor, factorise completely, then use the factorisation to simplify a rational expression or algebraic fraction.

4 questions

Edexcel C3 Q5
5. (a) Show that \(( 2 x + 3 )\) is a factor of \(\left( 2 x ^ { 3 } - x ^ { 2 } + 4 x + 15 \right)\).
(b) Hence, simplify $$\frac { 2 x ^ { 2 } + x - 3 } { 2 x ^ { 3 } - x ^ { 2 } + 4 x + 15 } .$$ (c) Find the coordinates of the stationary points of the curve with equation $$y = \frac { 2 x ^ { 2 } + x - 3 } { 2 x ^ { 3 } - x ^ { 2 } + 4 x + 15 } .$$
AQA C4 2011 January Q2
2
  1. The polynomial \(\mathrm { f } ( x )\) is defined by \(\mathrm { f } ( x ) = 9 x ^ { 3 } + 18 x ^ { 2 } - x - 2\).
    1. Use the Factor Theorem to show that \(3 x + 1\) is a factor of \(\mathrm { f } ( x )\).
    2. Express \(\mathrm { f } ( x )\) as a product of three linear factors.
    3. Simplify \(\frac { 9 x ^ { 3 } + 21 x ^ { 2 } + 6 x } { \mathrm { f } ( x ) }\).
  2. When the polynomial \(9 x ^ { 3 } + p x ^ { 2 } - x - 2\) is divided by \(3 x - 2\), the remainder is - 4 . Find the value of the constant \(p\).
AQA C4 2011 June Q1
1 The polynomial \(\mathrm { f } ( x )\) is defined by \(\mathrm { f } ( x ) = 4 x ^ { 3 } - 13 x + 6\).
  1. Find \(\mathrm { f } ( - 2 )\).
  2. Use the Factor Theorem to show that \(2 x - 3\) is a factor of \(\mathrm { f } ( x )\).
  3. Simplify \(\frac { 2 x ^ { 2 } + x - 6 } { \mathrm { f } ( x ) }\).
SPS SPS SM Pure 2024 June Q4
  1. In this question you must show all stages of your working.
Solutions based entirely on calculator technology are not acceptable. $$f ( x ) = 4 x ^ { 3 } - 4 x ^ { 2 } - 7 x - 2$$ a) Use the factor theorem to show that ( \(2 x + 1\) ) is a factor of \(f ( x )\).
b) Write \(\frac { 3 x + 4 } { f ( x ) }\) in partial fraction form.