Mathematics · OCR H240 · Topic 1.02

Algebra and functions

The algebra toolkit: indices, surds, quadratics, simultaneous equations, inequalities, polynomials, graph sketching, functions, transformations and partial fractions.

  • 11 sub-topics
  • 5 in Year 12, 3 in Year 13
  • 193 practice questions
  • 11 animated lessons

What the specification says

Every sub-topic OCR can examine in this topic, with its reference number from the official specification. The Y12 and Y13 tags show when each sub-topic is usually taught.

  1. 1.02aIndicesY12
  2. 1.02bSurdsY12
  3. 1.02cSimultaneous equationsY12
  4. 1.02d-fQuadratic functionsY12
  5. 1.02g-iInequalitiesY12
  6. 1.02j-kPolynomialsY13
  7. 1.02l-tThe modulus function and curve sketchingY13
  8. 1.02u-vFunctionsY13
  9. 1.02w-xGraph transformationsY13
  10. 1.02yPartial fractionsY13
  11. 1.02zModels in contextY13

Try 3 questions

Easy, medium and hard questions from this topic, each with a worked solutions and the mark for every step. All 193 questions in this topic, free, no account needed.

Algebra and functions

Easy

Equal roots · Year 12 · 3 marks

  1. The equation x2+kx+9=0x^2 + kx + 9 = 0 has equal roots. Find the possible values of kk.
    (3)
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  1. Equal (repeated) roots happen when the discriminant is zero.b2−4ac=0b^2 - 4ac = 0
  2. Here a=1a = 1, b=kb = k and c=9c = 9.k2−4×1×9k^2 - 4 \times 1 \times 9=0{}= 0⇒k2{}\Rightarrow k^2=36{}= 36
  3. Square-rooting gives two answers: positive and negative.k=6k = 6 or k=−6k = -6

Total3

  • MMethod mark: for a correct method, even with a slip.
  • AAccuracy mark: for a correct answer from a correct method.
  • BIndependent mark: for a correct fact or result on its own, with no method needed.
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Algebra and functions

Not needed for Year 12Medium

Partial fractions · Year 13 · 3 marks

  1. Express 5x+1(x−1)(x+2)\dfrac{5x + 1}{(x - 1)(x + 2)} in partial fractions.
    (3)
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  1. Write it as Ax−1\dfrac{A}{x - 1}+Bx+2{}+ \dfrac{B}{x + 2} and multiply through.5x+1=A(x+2)+B(x−1)5x + 1 = A(x + 2) + B(x - 1)
  2. Choose values of xx that make one bracket zero.x=1x = 1: 6=3A⇒A=26 = 3A \Rightarrow A = 2; x=−2x = -2: −9=−3B⇒B=3-9 = -3B \Rightarrow B = 3
  3. 2x−1\dfrac{2}{x - 1}+3x+2{}+ \dfrac{3}{x + 2}

Total3

  • MMethod mark: for a correct method, even with a slip.
  • AAccuracy mark: for a correct answer from a correct method.
  • BIndependent mark: for a correct fact or result on its own, with no method needed.
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Algebra and functions

Hard

Roots and the discriminant · Year 12 · 5 marks

  1. Find the values of kk for which kx2+4x+(k−3)=0kx^2 + 4x + (k - 3) = 0 has two distinct real roots.
    (5)
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  1. Two distinct real roots means the discriminant is positive.b2−4ac>0b^2 - 4ac > 0: 16−4k(k−3)>016 - 4k(k - 3) > 0
  2. Divide by −4-4, which reverses the inequality.k2−3k−4<0k^2 - 3k - 4 < 0
  3. Critical values −1-1 and 44; a ∪ shape is negative between them.(k−4)(k+1)<0(k - 4)(k + 1) < 0, so −1<k<4-1 < k < 4
  4. If k=0k = 0 the equation is not a quadratic and has only one root.−1<k<4-1 < k < 4, k≠0k \ne 0

Total5

  • MMethod mark: for a correct method, even with a slip.
  • AAccuracy mark: for a correct answer from a correct method.
  • BIndependent mark: for a correct fact or result on its own, with no method needed.
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