Admissions tests / TMUA / Paper 1 / Algebra and functions
Test standard. 12 questions, 12 marks, about 48 minutes.
TMUA Paper 1: Algebra and functions, set 2
Indices, surds, quadratics, simultaneous equations, inequalities, polynomials and the factor theorem, applied in contexts that hide which technique is wanted.
Download the questions (PDF) Download with worked solutions (PDF)
- Answer all questions. No calculator.
- Each question has exactly one correct answer.
- 11 mark
Simplify (x^4 y^(-6))^(1/2) / (x^(-1) y^2) fully.
- 21 mark
Simplify sqrt(50) + sqrt(18) - sqrt(8) fully.
- 31 mark
The equation 3x^2 + kx + 12 = 0 has no real roots. What is the range of possible values of k?
- 41 mark
By completing the square, solve x^2 + 8x + 10 = 0, giving your answers in the form p +/- sqrt(q).
- 51 mark
The line y = mx + 4 is a tangent to the curve y = x^2 + 2x + 7. Find the possible values of m.
- 61 mark
Find the set of values of x for which -x^2 + 2x + 8 >= 0.
- 71 mark
Solve the inequality 5 - 2x >= 3x - 15 for x.
- 81 mark
Expand and simplify (x + 3)(2x - 1)(x - 2).
- 91 mark
When 4x^3 - 4x^2 - 5x - 1 is divided by (2x + 1), the quotient is ax^2 + bx + c. Find the value of a + b + c.
- 101 mark
The cubic p(x) = 2x^3 - x^2 + kx - 10 has (x - 2) as a factor. What is the remainder when p(x) is divided by (x + 1)?
- 111 mark
Solve the equation |2x - 5| = |x + 4|. What is the sum of the solutions?
- 121 mark
The graph of y = x^2 + bx + c has a minimum point at (3, -4). What is the value of b + c?
Worked solutions
Every question below carries the reasoning, not just the answer. The official material for this test publishes a correct option letter and nothing else.
Question 1Answer: C
- Apply the outer power 1/2 to each factor inside the bracket: (x^4)^(1/2) = x^2 and (y^(-6))^(1/2) = y^(-3), so the bracket simplifies to x^2 y^(-3).
- Divide by x^(-1) y^2 by subtracting exponents: for x, 2 - (-1) = 3; for y, -3 - 2 = -5.
- This gives x^3 y^(-5), which is x^3/y^5.
- So the fully simplified expression is x^3/y^5, which is option C.
- Why not A: Divides by adding indices instead of subtracting: computes x^(2 + (-1)) y^(-3 + 2) = x/y rather than subtracting each exponent.
- Why not B: Misreads the sign of the denominator's y^2, treating it as y^(-2), so computes the y index as -3 - (-2) = -1 instead of -3 - 2 = -5.
- Why not D: Applies the outer power 1/2 to the x term inside the bracket but not to the y term, leaving y^(-6) instead of halving it to y^(-3), so the y index ends up as -6 - 2 = -8.
Question 2Answer: A
- Write each surd in simplified form: sqrt(50) = sqrt(25 x 2) = 5 sqrt(2).
- Similarly sqrt(18) = sqrt(9 x 2) = 3 sqrt(2) and sqrt(8) = sqrt(4 x 2) = 2 sqrt(2).
- Combine like surds: 5 sqrt(2) + 3 sqrt(2) - 2 sqrt(2) = 6 sqrt(2).
- So the expression simplifies to 6 sqrt(2), which is option A.
- Why not B: Treats sqrt(a) + sqrt(b) as sqrt(a + b), adding the numbers under the root directly to get sqrt(50 + 18 - 8) = sqrt(60), instead of simplifying each surd first.
- Why not C: Simplifies sqrt(18) as 9 sqrt(2) instead of 3 sqrt(2), taking the whole factor 9 out front rather than its square root.
- Why not D: Treats the final subtraction as an addition, computing 5 sqrt(2) + 3 sqrt(2) + 2 sqrt(2) instead of 5 sqrt(2) + 3 sqrt(2) - 2 sqrt(2).
Question 3Answer: D
- A quadratic has no real roots exactly when its discriminant b^2 - 4ac is negative.
- Here a = 3, b = k and c = 12, so the discriminant is k^2 - 4(3)(12) = k^2 - 144.
- Setting k^2 - 144 < 0 gives k^2 < 144, which means -12 < k < 12.
- So the range of values is -12 < k < 12, which is option D.
- Why not A: Uses the condition for the equation to HAVE two real roots (discriminant >= 0) instead of no real roots (discriminant < 0), giving the region outside -12 and 12 rather than between them.
- Why not B: Solves k^2 < 144 by dropping the square root step, treating it as k < 144 directly rather than -12 < k < 12.
- Why not C: Takes only the positive square root of 144, missing the lower bound and giving k < 12 instead of -12 < k < 12.
Question 4Answer: B
- Half the coefficient of x is 4, so x^2 + 8x + 10 = (x + 4)^2 - 16 + 10 = (x + 4)^2 - 6.
- Setting (x + 4)^2 - 6 = 0 gives (x + 4)^2 = 6, so x + 4 = +/- sqrt(6).
- Solving for x gives x = -4 +/- sqrt(6).
- So the solutions are x = -4 +/- sqrt(6), which is option B.
- Why not A: Uses p = 8 instead of half of 8 when completing the square, writing (x + 8)^2 - 64 + 10 instead of (x + 4)^2 - 16 + 10.
- Why not C: Completes the square correctly to (x + 4)^2 - 6 = 0 but then forgets to negate p when writing the final solutions, giving x = 4 +/- sqrt(6) instead of x = -4 +/- sqrt(6).
- Why not D: Combines the constants -16 and +10 with a sign slip, computing -16 - 10 = -26 instead of -16 + 10 = -6.
Question 5Answer: A
- At a point where the line meets the curve, mx + 4 = x^2 + 2x + 7, so x^2 + (2 - m)x + 3 = 0.
- A line is a tangent to a curve exactly when this equation has a repeated root, so its discriminant is zero: (2 - m)^2 - 4(1)(3) = 0.
- This gives (2 - m)^2 = 12, so 2 - m = +/- 2 sqrt(3). Rearranging each case gives m = 2 - 2 sqrt(3) or m = 2 + 2 sqrt(3).
- So the possible values are m = 2 +/- 2 sqrt(3), which is option A.
- Why not B: Makes a sign error moving mx across when forming the quadratic, writing x^2 + (2 + m)x + 3 = 0 instead of x^2 + (2 - m)x + 3 = 0.
- Why not C: Uses the condition b^2 - ac = 0 instead of the correct discriminant b^2 - 4ac = 0, dropping the factor of 4.
- Why not D: Forgets to subtract the 4 from the constant term when setting the two expressions equal, using 7 instead of 3 as the constant in the resulting quadratic.
Question 6Answer: D
- Multiply both sides by -1, remembering to reverse the inequality: x^2 - 2x - 8 <= 0.
- Factorise: x^2 - 2x - 8 = (x - 4)(x + 2), with roots x = 4 and x = -2.
- Since the coefficient of x^2 is positive, the expression is <= 0 between the roots.
- So the solution is -2 <= x <= 4, which is option D.
- Why not A: Combines both other errors: uses the wrong-signed root 2 instead of -2, and also takes the region outside the roots rather than between them.
- Why not B: Reads the roots of (x - 4)(x + 2) as 4 and 2, forgetting that x + 2 = 0 gives x = -2, not x = 2.
- Why not C: Multiplies both sides by -1 to clear the leading minus sign but forgets to reverse the inequality, so ends up with the region outside the roots instead of between them.
Question 7Answer: C
- Collect the x-terms on one side and the constants on the other: 5 + 15 >= 3x + 2x, that is 20 >= 5x.
- Divide both sides by 5, a positive number, so the inequality is unchanged: 4 >= x, that is x <= 4.
- So the solution is x <= 4, which is option C.
- Why not A: Combines the x-terms -2x and -3x incorrectly as -x instead of -5x, effectively solving -x >= -20 and then dividing by -1.
- Why not B: Divides both sides of -5x >= -20 by -5 without reversing the direction of the inequality.
- Why not D: Makes an arithmetic slip moving the constant, computing -5x >= -15 - 5 as -5x >= -10 instead of -5x >= -20.
Question 8Answer: B
- First expand (x + 3)(2x - 1) = 2x^2 - x + 6x - 3 = 2x^2 + 5x - 3.
- Multiply this by (x - 2): (2x^2 + 5x - 3)(x - 2) = 2x^3 - 4x^2 + 5x^2 - 10x - 3x + 6.
- Collect like terms: 2x^3 + x^2 - 13x + 6.
- So the fully expanded expression is 2x^3 + x^2 - 13x + 6, which is option B.
- Why not A: Drops the cross term -x when expanding (x + 3)(2x - 1), using 2x^2 + 6x - 3 instead of 2x^2 + 5x - 3, before multiplying by (x - 2).
- Why not C: Misreads the final bracket as (x + 2) instead of (x - 2), flipping the sign of every term that comes from it.
- Why not D: Combines the two x^2 contributions -4x^2 and +5x^2 with the wrong sign, getting -9x^2 instead of +x^2.
Question 9Answer: D
- Write (2x + 1)(ax^2 + bx + c) = 4x^3 - 4x^2 - 5x - 1 and expand the left side: 2a x^3 + (2b + a) x^2 + (2c + b) x + c.
- Match the x^3 coefficients: 2a = 4, so a = 2. Match the constant terms: c = -1.
- Match the x^2 coefficients: 2b + a = -4, so 2b = -6 and b = -3. (Check the x coefficient: 2c + b = -2 - 3 = -5, which agrees.)
- So a = 2, b = -3, c = -1, and a + b + c = -2, which is option D.
- Why not A: Misreads the sign of the dividend's constant term, taking c = 1 instead of c = -1.
- Why not B: Drops the a term when matching the x^2 coefficients, solving 2b = -4 instead of 2b + a = -4, giving b = -2 instead of b = -3.
- Why not C: Misreads the sign of the dividend's x^2 coefficient when setting up the comparison, using +4 instead of -4.
Question 10Answer: A
- Since (x - 2) is a factor, the Factor Theorem gives p(2) = 0: 2(8) - 4 + 2k - 10 = 0, so 2 + 2k = 0 and k = -1.
- So p(x) = 2x^3 - x^2 - x - 10.
- By the Remainder Theorem, the remainder when p(x) is divided by (x + 1) is p(-1) = 2(-1)^3 - (-1)^2 - (-1) - 10.
- This equals -2 - 1 + 1 - 10 = -12, which is option A.
- Why not B: Miscalculates 2^3 as 6 instead of 8 when substituting into the factor theorem equation, giving k = 1 instead of k = -1.
- Why not C: Treats (-1) raised to an odd power as positive, evaluating (-1)^3 as +1 when computing the remainder.
- Why not D: Evaluates p(1) instead of p(-1), confusing which value of x corresponds to the factor (x + 1).
Question 11Answer: C
- An equation of the form |A| = |B| holds exactly when A = B or A = -B, so consider both cases.
- Case 1: 2x - 5 = x + 4 gives x = 9.
- Case 2: 2x - 5 = -(x + 4) gives 2x - 5 = -x - 4, so 3x = 1 and x = 1/3.
- The sum of the two solutions is 9 + 1/3 = 28/3, which is option C.
- Why not A: Only finds the solution from the case 2x - 5 = x + 4, missing the second case entirely.
- Why not B: Finds both solutions but makes a sign error distributing the negative in the second case, writing 2x - 5 = -x + 4 instead of 2x - 5 = -x - 4, giving x = 3 instead of x = 1/3, and so a sum of 9 + 3 = 12.
- Why not D: Only finds the solution from the case 2x - 5 = -(x + 4), missing the first case entirely.
Question 12Answer: B
- A quadratic with minimum point (h, k) can be written as y = (x - h)^2 + k, so here y = (x - 3)^2 - 4.
- Expand: (x - 3)^2 - 4 = x^2 - 6x + 9 - 4 = x^2 - 6x + 5.
- Comparing with y = x^2 + bx + c gives b = -6 and c = 5, so b + c = -1.
- So b + c = -1, which is option B.
- Why not A: Writes the vertex form with the wrong sign, using (x + 3)^2 - 4 instead of (x - 3)^2 - 4.
- Why not C: Expands (x - 3)^2 as x^2 - 9, forgetting the middle term -6x, as though squaring a bracket simply squares each part.
- Why not D: Swaps the vertex coordinates, using -4 as the horizontal shift and 3 as the vertical shift, giving (x + 4)^2 + 3 instead of (x - 3)^2 - 4.
More free TMUA practice
Every strand of the published TMUA specification, with worked solutions throughout.