Single polynomial, two remainder/factor conditions

Questions with one polynomial where two conditions (factor or remainder) are given to find two constants, followed by factorisation or further work.

26 questions · Moderate -0.5

CAIE P3 Specimen Q6
Moderate -0.8
6 The polynomial \(8 x ^ { 3 } + a x ^ { 2 } + b x - 1\), where \(a\) and \(b\) are constants, is denoted by \(\mathrm { p } ( x )\). It is given that \(( x + 1 )\) is a factor of \(\mathrm { p } ( x )\) and that when \(\mathrm { p } ( x )\) is divided by ( \(2 x + 1\) ) the remainder is 1 .
  1. Find the values of \(a\) and \(b\).
  2. When \(a\) and \(b\) have these values, factorise \(\mathrm { p } ( x )\) completely.
CAIE P2 2019 June Q5
Moderate -0.8
5 The polynomial \(\mathrm { p } ( x )\) is defined by $$\mathrm { p } ( x ) = 5 x ^ { 3 } + a x ^ { 2 } + b x - 16$$ where \(a\) and \(b\) are constants. It is given that \(( x - 2 )\) is a factor of \(\mathrm { p } ( x )\) and that the remainder is 27 when \(\mathrm { p } ( x )\) is divided by \(( x + 1 )\).
  1. Find the values of \(a\) and \(b\).
  2. Hence factorise \(\mathrm { p } ( x )\) completely.
CAIE P2 2017 March Q6
Moderate -0.3
6 The polynomial \(\mathrm { p } ( x )\) is defined by $$\mathrm { p } ( x ) = a x ^ { 3 } + b x ^ { 2 } - 17 x - a$$ where \(a\) and \(b\) are constants. It is given that \(( x + 2 )\) is a factor of \(\mathrm { p } ( x )\) and that the remainder is 28 when \(\mathrm { p } ( x )\) is divided by \(( x - 2 )\).
  1. Find the values of \(a\) and \(b\).
  2. Hence factorise \(\mathrm { p } ( x )\) completely.
  3. State the number of roots of the equation \(\mathrm { p } \left( 2 ^ { y } \right) = 0\), justifying your answer.
    \includegraphics[max width=\textwidth, alt={}, center]{17025451-6f07-4f35-9dfc-869e084b5ed0-10_508_538_310_799} The diagram shows part of the curve $$y = 2 \cos 2 x \cos \left( 2 x + \frac { 1 } { 6 } \pi \right)$$ The shaded region is bounded by the curve and the two axes.
  4. Show that \(2 \cos 2 x \cos \left( 2 x + \frac { 1 } { 6 } \pi \right)\) can be expressed in the form $$k _ { 1 } ( 1 + \cos 4 x ) + k _ { 2 } \sin 4 x ,$$ where the values of the constants \(k _ { 1 }\) and \(k _ { 2 }\) are to be determined.
  5. Find the exact area of the shaded region.
CAIE P2 2002 November Q2
Moderate -0.8
2 The cubic polynomial \(2 x ^ { 3 } + a x ^ { 2 } + b\) is denoted by \(\mathrm { f } ( x )\). It is given that ( \(x + 1\) ) is a factor of \(\mathrm { f } ( x )\), and that when \(\mathrm { f } ( x )\) is divided by \(( x + 2 )\) the remainder is - 5 . Find the values of \(a\) and \(b\).
CAIE P2 2004 November Q4
Moderate -0.8
4 The cubic polynomial \(2 x ^ { 3 } - 5 x ^ { 2 } + a x + b\) is denoted by \(\mathrm { f } ( x )\). It is given that ( \(x - 2\) ) is a factor of \(\mathrm { f } ( x )\), and that when \(\mathrm { f } ( x )\) is divided by \(( x + 1 )\) the remainder is - 6 . Find the values of \(a\) and \(b\).
CAIE P2 2010 November Q7
Moderate -0.8
7 The polynomial \(3 x ^ { 3 } + 2 x ^ { 2 } + a x + b\), where \(a\) and \(b\) are constants, is denoted by \(\mathrm { p } ( x )\). It is given that \(( x - 1 )\) is a factor of \(\mathrm { p } ( x )\), and that when \(\mathrm { p } ( x )\) is divided by \(( x - 2 )\) the remainder is 10 .
  1. Find the values of \(a\) and \(b\).
  2. When \(a\) and \(b\) have these values, solve the equation \(\mathrm { p } ( x ) = 0\).
CAIE P2 2011 November Q7
Moderate -0.8
7 The polynomial \(a x ^ { 3 } - 3 x ^ { 2 } - 11 x + b\), where \(a\) and \(b\) are constants, is denoted by \(\mathrm { p } ( x )\). It is given that \(( x + 2 )\) is a factor of \(\mathrm { p } ( x )\), and that when \(\mathrm { p } ( x )\) is divided by \(( x + 1 )\) the remainder is 12 .
  1. Find the values of \(a\) and \(b\).
  2. When \(a\) and \(b\) have these values, factorise \(\mathrm { p } ( x )\) completely.
CAIE P2 2017 November Q5
Moderate -0.3
5 The polynomial \(\mathrm { p } ( x )\) is defined by $$\mathrm { p } ( x ) = a x ^ { 3 } + b x ^ { 2 } + 37 x + 10$$ where \(a\) and \(b\) are constants. It is given that \(( x + 2 )\) is a factor of \(\mathrm { p } ( x )\). It is also given that the remainder is 40 when \(\mathrm { p } ( x )\) is divided by ( \(2 x - 1\) ).
  1. Find the values of \(a\) and \(b\).
  2. When \(a\) and \(b\) have these values, factorise \(\mathrm { p } ( x )\) completely.
CAIE P3 2022 June Q3
Moderate -0.3
3 The polynomial \(a x ^ { 3 } + x ^ { 2 } + b x + 3\) is denoted by \(\mathrm { p } ( x )\). It is given that \(\mathrm { p } ( x )\) is divisible by ( \(2 x - 1\) ) and that when \(\mathrm { p } ( x )\) is divided by \(( x + 2 )\) the remainder is 5 . Find the values of \(a\) and \(b\).
CAIE P3 2021 March Q2
Moderate -0.5
2 The polynomial \(a x ^ { 3 } + 5 x ^ { 2 } - 4 x + b\), where \(a\) and \(b\) are constants, is denoted by \(\mathrm { p } ( x )\). It is given that \(( x + 2 )\) is a factor of \(\mathrm { p } ( x )\) and that when \(\mathrm { p } ( x )\) is divided by \(( x + 1 )\) the remainder is 2 . Find the values of \(a\) and \(b\).
CAIE P3 2023 November Q3
Moderate -0.8
3 The polynomial \(2 x ^ { 3 } + a x ^ { 2 } - 11 x + b\) is denoted by \(\mathrm { p } ( x )\). It is given that \(\mathrm { p } ( x )\) is divisible by \(( 2 x - 1 )\) and that when \(\mathrm { p } ( x )\) is divided by \(( x + 1 )\) the remainder is 12 . Find the values of \(a\) and \(b\).
Edexcel C12 2015 January Q10
Moderate -0.3
10. $$f ( x ) = 6 x ^ { 3 } + a x ^ { 2 } + b x - 5$$ where \(a\) and \(b\) are constants. When \(\mathrm { f } ( x )\) is divided by \(( x + 1 )\) there is no remainder.
When \(\mathrm { f } ( x )\) is divided by ( \(2 x - 1\) ) the remainder is - 15
  1. Find the value of \(a\) and the value of \(b\).
  2. Factorise \(\mathrm { f } ( x )\) completely.
Edexcel C12 2018 January Q6
Moderate -0.3
6. $$f ( x ) = a x ^ { 3 } - 8 x ^ { 2 } + b x + 6$$ where \(a\) and \(b\) are constants. When \(\mathrm { f } ( x )\) is divided by ( \(x + 1\) ) there is no remainder. When \(\mathrm { f } ( x )\) is divided by \(( x - 2 )\) the remainder is - 12
  1. Find the value of \(a\) and the value of \(b\).
  2. Factorise \(\mathrm { f } ( x )\) completely.
Edexcel C2 2005 January Q5
Moderate -0.8
  1. \(\quad \mathrm { f } ( x ) = x ^ { 3 } - 2 x ^ { 2 } + a x + b\), where \(a\) and \(b\) are constants.
When \(\mathrm { f } ( x )\) is divided by ( \(x - 2\) ), the remainder is 1 .
When \(\mathrm { f } ( x )\) is divided by \(( x + 1 )\), the remainder is 28 .
  1. Find the value of \(a\) and the value of \(b\).
  2. Show that ( \(x - 3\) ) is a factor of \(\mathrm { f } ( x )\).
Edexcel C2 2013 June Q4
Moderate -0.3
4. \(\mathrm { f } ( x ) = a x ^ { 3 } - 11 x ^ { 2 } + b x + 4\), where \(a\) and \(b\) are constants. When \(\mathrm { f } ( x )\) is divided by ( \(x - 3\) ) the remainder is 55
When \(\mathrm { f } ( x )\) is divided by \(( x + 1 )\) the remainder is - 9
  1. Find the value of \(a\) and the value of \(b\). Given that \(( 3 x + 2 )\) is a factor of \(\mathrm { f } ( x )\),
  2. factorise \(\mathrm { f } ( x )\) completely.
OCR C2 2006 June Q8
Moderate -0.3
8 The cubic polynomial \(2 x ^ { 3 } + a x ^ { 2 } + b x - 10\) is denoted by \(\mathrm { f } ( x )\). It is given that, when \(\mathrm { f } ( x )\) is divided by \(( x - 2 )\), the remainder is 12 . It is also given that ( \(x + 1\) ) is a factor of \(\mathrm { f } ( x )\).
  1. Find the values of \(a\) and \(b\).
  2. Divide \(\mathrm { f } ( x )\) by ( \(x + 2\) ) to find the quotient and the remainder.
OCR MEI C1 2012 June Q8
Moderate -0.3
8 The function \(\mathrm { f } ( x ) = x ^ { 4 } + b x + c\) is such that \(\mathrm { f } ( 2 ) = 0\). Also, when \(\mathrm { f } ( x )\) is divided by \(x + 3\), the remainder is 85 . Find the values of \(b\) and \(c\).
OCR MEI C1 2016 June Q8
Moderate -0.8
8 You are given that \(\mathrm { f } ( x ) = x ^ { 3 } + a x + c\) and that \(\mathrm { f } ( 2 ) = 11\). The remainder when \(\mathrm { f } ( x )\) is divided by \(( x + 1 )\) is 8 . Find the values of \(a\) and \(c\).
OCR C2 2010 January Q6
Moderate -0.3
6 The cubic polynomial \(\mathrm { f } ( x )\) is given by $$\mathrm { f } ( x ) = 2 x ^ { 3 } + a x ^ { 2 } + b x + 15$$ where \(a\) and \(b\) are constants. It is given that ( \(x + 3\) ) is a factor of \(\mathrm { f } ( x )\) and that, when \(\mathrm { f } ( x )\) is divided by ( \(x - 2\) ), the remainder is 35 .
  1. Find the values of \(a\) and \(b\).
  2. Using these values of \(a\) and \(b\), divide \(\mathrm { f } ( x )\) by ( \(x + 3\) ).
Edexcel C2 Q6
Moderate -0.3
6. \(\mathrm { f } ( x ) = 6 x ^ { 3 } + p x ^ { 2 } + q x + 8\), where \(p\) and \(q\) are constants. Given that \(\mathrm { f } ( x )\) is exactly divisible by ( \(2 x - 1\) ), and also that when \(\mathrm { f } ( x )\) is divided by ( \(x - 1\) ) the remainder is - 7 ,
  1. find the value of \(p\) and the value of \(q\).
  2. Hence factorise \(\mathrm { f } ( x )\) completely.
Edexcel C2 Q1
Moderate -0.3
  1. \(\mathrm { f } ( x ) = x ^ { 3 } + a x ^ { 2 } + b x - 10\), where \(a\) and \(b\) are constants.
When \(\mathrm { f } ( x )\) is divided by ( \(x - 3\) ), the remainder is 14 .
When \(\mathrm { f } ( x )\) is divided by ( \(x + 1\) ), the remainder is - 18 .
  1. Find the value of \(a\) and the value of \(b\).
  2. Show that ( \(x - 2\) ) is a factor of \(\mathrm { f } ( x )\).
Edexcel C2 Q7
Moderate -0.8
7
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  1. \(\mathrm { f } ( x ) = x ^ { 3 } + a x ^ { 2 } + b x - 10\), where \(a\) and \(b\) are constants.
When \(\mathrm { f } ( x )\) is divided by ( \(x - 3\) ), the remainder is 14 .
When \(\mathrm { f } ( x )\) is divided by ( \(x + 1\) ), the remainder is - 18 .
  1. Find the value of \(a\) and the value of \(b\).
  2. Show that ( \(x - 2\) ) is a factor of \(\mathrm { f } ( x )\).
    2. (a) Write down the first four terms of the binomial expansion, in ascending powers of \(x\), of \(( 1 + a x ) ^ { n }\), where \(n > 2\). Given that, in this expansion, the coefficient of \(x\) is 8 and the coefficient of \(x ^ { 2 }\) is 30 ,
  3. find the value of \(n\) and the value of \(a\),
  4. find the coefficient of \(x ^ { 3 }\).
    3. A population of deer is introduced into a park. The population \(P\) at \(t\) years after the deer have been introduced is modelled by $$P = \frac { 2000 a ^ { t } } { 4 + a ^ { t } } ,$$ where \(a\) is a constant. Given that there are 800 deer in the park after 6 years,
  5. calculate, to 4 decimal places, the value of \(a\),
  6. use the model to predict the number of years needed for the population of deer to increase from 800 to 1800.
  7. With reference to this model, give a reason why the population of deer cannot exceed 2000.
    4. Given that \(\mathrm { f } ( x ) = \left( 2 x ^ { \frac { 3 } { 2 } } - 3 x ^ { - \frac { 3 } { 2 } } \right) ^ { 2 } + 5 , \quad x > 0\),
  8. find, to 3 significant figures, the value of \(x\) for which \(\mathrm { f } ( x ) = 5\).
  9. Show that \(\mathrm { f } ( x )\) may be written in the form \(A x ^ { 3 } + \frac { B } { x ^ { 3 } } + C\), where \(A , B\) and \(C\) are constants to be found.
  10. Hence evaluate \(\int _ { 1 } ^ { 2 } f ( x ) d x\).
    5. \begin{figure}[h]
    \captionsetup{labelformat=empty} \caption{Figure 1} \includegraphics[alt={},max width=\textwidth]{5e4e4cae-d4c6-465d-8cb7-84712e6e55fe-3_736_1266_276_404}
    \end{figure} Figure 1 shows the cross-section \(A B C D\) of a chocolate bar, where \(A B , C D\) and \(A D\) are straight lines and \(M\) is the mid-point of \(A D\). The length \(A D\) is 28 mm , and \(B C\) is an arc of a circle with centre \(M\). Taking \(A\) as the origin, \(B , C\) and \(D\) have coordinates \(( 7,24 ) , ( 21,24 )\) and \(( 28,0 )\) respectively.
  11. Show that the length of \(B M\) is 25 mm .
  12. Show that, to 3 significant figures, \(\angle B M C = 0.568\) radians.
  13. Hence calculate, in \(\mathrm { mm } ^ { 2 }\), the area of the cross-section of the chocolate bar. Given that this chocolate bar has length 85 mm ,
  14. calculate, to the nearest \(\mathrm { cm } ^ { 3 }\), the volume of the bar.
    6. \begin{figure}[h]
    \includegraphics[alt={},max width=\textwidth]{5e4e4cae-d4c6-465d-8cb7-84712e6e55fe-4_641_1406_196_287} \captionsetup{labelformat=empty} \caption{Fig. 1}
    \end{figure} Figure 1 shows the curve with equation \(y = 5 + 2 x - x ^ { 2 }\) and the line with equation \(y = 2\). The curve and the line intersect at the points \(A\) and \(B\).
  15. Find the x-coordinates of \(A\) and \(B\). The shaded region \(R\) is bounded by the curve and the line.
  16. Find the area of \(R\).
    7. Find all the values of \(\theta\) in the interval \(0 \leq \theta < 360 ^ { \circ }\) for which
  17. \(\cos \left( \theta - 10 ^ { \circ } \right) = \cos 15 ^ { \circ }\),
  18. \(\tan 2 \theta = 0.4\),
  19. \(2 \sin \theta \tan \theta = 3\).
Edexcel C2 Q2
Moderate -0.5
2. \(\mathrm { f } ( x ) = x ^ { 3 } + a x ^ { 2 } + b x - 10\), where \(a\) and \(b\) are constants. When \(\mathrm { f } ( x )\) is divided by \(( x - 3 )\), the remainder is 14 . When \(\mathrm { f } ( x )\) is divided by \(( x + 1 )\), the remainder is - 18 .
  1. Find the value of \(a\) and the value of \(b\).
  2. Show that \(( x - 2 )\) is a factor of \(\mathrm { f } ( x )\).
    [0pt] [P3 June 2002 Question 1]
Edexcel C2 Q6
Moderate -0.3
6. The polynomial \(\mathrm { p } ( x )\) is defined by $$\mathrm { p } ( x ) = 2 x ^ { 3 } + x ^ { 2 } + a x + b ,$$ where \(a\) and \(b\) are constants.
Given that when \(\mathrm { p } ( x )\) is divided by \(( x + 2 )\) there is a remainder of 20 ,
  1. find an expression for \(b\) in terms of \(a\). Given also that \(( x + 3 )\) is a factor of \(\mathrm { p } ( x )\),
  2. find the values of \(a\) and \(b\),
  3. fully factorise \(\mathrm { p } ( x )\).
SPS SPS SM 2025 October Q10
Moderate -0.3
10. \(f ( x ) = x ^ { 4 } + b x + c\)
\(( x - 2 )\) is a factor of \(f ( x )\).
\(f ( - 3 ) = 35\).
  1. Find b and c.
  2. Hence express \(\mathrm { f } ( \mathrm { x } )\) as the product of linear and cubic factors.
    [0pt] [BLANK PAGE]