IGCSE · Mathematics 0580 · Coordinate geometry

Gradient & equation of a line: IGCSE Mathematics questions with answers

Free Gradient & equation of a line questions for IGCSE Mathematics (0580), part of Coordinate geometry. Each question has the answer and the marking points an examiner would look for.

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Gradient & equation of a line practice questions

Question 1Structured · 4 marksA* challenge

The line L has gradient 2 and passes through the point (2, 9).
L crosses the x-axis at A and the y-axis at B. O is the origin.
Find the area of triangle OAB.

[4]
Show answers and mark scheme
PartAnswer and marking pointsMarks
254
y = 2x + 5 M1
B = (0, 5), A = (−52, 0) A1
½ × base × height M1
254 A1
4
Question 2Structured · 11 marksA* challenge

The line L has equation y = 2x.
A is the point (1, 7) and B is the point (3, 9). A and B are on the same side of L.

(a)

Find the coordinates of the point on L that is nearest to A, and the exact shortest distance from A to L.

[3]
(b)

P is a point on L. Find the coordinates of P for which AP + PB is as small as possible, and the exact value of this least distance.

[5]
(c)

Q is a point on L. Find the coordinates of Q for which QA − QB is as large as possible, and the exact value of this greatest difference.

[3]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)(3, 6); √5
line through A perpendicular to L: y − 7 = −½(x − 1) M1
meets y = 2x at (3, 6) A1
√(22 + 12) = √5 A1
3
(b)P = (3.75, 7.5); least AP + PB = 2√5
reflects A in L: A′ = (5, 5) M1
A′ = 2(3, 6) − (1, 7) A1
least AP + PB is when P is on A′B: y = −2x + 15 M1
P = (3.75, 7.5) A1
A′B = √(22 + 42) = 2√5 A1
5
(c)Q = (6, 12); 2√2
QA − QB ≤ AB, with equality when Q, B, A are collinear: line AB is y = x + 6 M1
Q = (6, 12) A1
AB = 2√2 A1
3
Question 3Structured · 4 marks

The equation of a line is 3x + 6y = 36.

(a)

Find the gradient of the line.

[2]
(b)

Find the coordinates of the points where the line crosses the x-axis and the y-axis.

[2]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)−12
rearranges to y = … M1
−12 A1
2
(b)(12, 0) and (0, 6)
(12, 0) B1
(0, 6) B1
2
Question 4Structured · 6 marks

The diagram shows the line L.

−5−4−3−2−112345−5−4−3−2−1123450xyL
Fig. 4.1
(a)

Find the gradient of line L.

[2]
(b)

Find the equation of line L in the form y = mx + c.

[2]
(c)

Find the equation of the line parallel to L that passes through the point (−6, 3).

[2]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)−12
−48 using two points on the line M1
−12 A1
2
(b)y = −12x − 1
y = −12x − 1 B2
B1 for correct gradient or correct intercept in y = mx + c
2
(c)y = −12x
3 = −12 × −6 + c M1
y = −12x A1
2
Question 5Structured · 4 marksA* challenge

The line L has gradient −1 and passes through the point (2, −5).
L crosses the x-axis at A and the y-axis at B. O is the origin.
Find the area of triangle OAB.

[4]
Show answers and mark scheme
PartAnswer and marking pointsMarks
92
y = −x − 3 M1
B = (0, −3), A = (−3, 0) A1
½ × base × height M1
92 A1
4
Question 6Structured · 4 marks

The equation of a line is 2x + 3y = 12.

(a)

Find the gradient of the line.

[2]
(b)

Find the coordinates of the points where the line crosses the x-axis and the y-axis.

[2]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)−23
rearranges to y = … M1
−23 A1
2
(b)(6, 0) and (0, 4)
(6, 0) B1
(0, 4) B1
2

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Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in