AQA Paper 1 Specimen — Question 7 4 marks

Exam BoardAQA
ModulePaper 1 (Paper 1)
SessionSpecimen
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicDiscriminant and conditions for roots
TypeFind k for equal roots
DifficultyModerate -0.3 This is a standard discriminant problem requiring students to apply the condition b² - 4ac = 0 for equal roots, then solve the resulting quadratic equation in k. It's slightly easier than average because it follows a well-practiced procedure with no conceptual surprises, though algebraic manipulation requires care.
Spec1.02d Quadratic functions: graphs and discriminant conditions

Find the values of \(k\) for which the equation \((2k - 3)x^2 - kx + (k - 1) = 0\) has equal roots. [4 marks]

Question 7:
AnswerMarks Guidance
7Clearly states that
equal roots b2 4ac0AO2.4 B1
k24(2k3)(k1)0
7k2 20k120
6
k  ,k 2
7
Forms quadratic expression in k
AnswerMarks Guidance
(allow one error)AO1.1a M1
Obtains correct quadratic equation in k
AnswerMarks Guidance
(PI by correct values for k)AO1.1b A1
Obtains correct values for k for ‘their’
AnswerMarks Guidance
quadratic equationAO1.1b A1F
Total4
QMarking Instructions AO
Question 7:
7 | Clearly states that
equal roots b2 4ac0 | AO2.4 | B1 | b24ac0for equal roots
k24(2k3)(k1)0
7k2 20k120
6
k  ,k 2
7
Forms quadratic expression in k
(allow one error) | AO1.1a | M1
Obtains correct quadratic equation in k
(PI by correct values for k) | AO1.1b | A1
Obtains correct values for k for ‘their’
quadratic equation | AO1.1b | A1F
Total | 4
Q | Marking Instructions | AO | Marks | Typical Solution
Find the values of $k$ for which the equation $(2k - 3)x^2 - kx + (k - 1) = 0$ has equal roots.
[4 marks]

\hfill \mbox{\textit{AQA Paper 1  Q7 [4]}}