IB · Mathematics: Applications & Interpretation SL & HL · Calculus

Differential equations & Euler’s method: IB Mathematics: Applications & Interpretation questions with answers

Free Differential equations & Euler’s method questions for IB Mathematics: Applications & Interpretation (SL & HL), HL only, part of Calculus. Each question has the answer and the marking points an examiner would look for.

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Differential equations & Euler’s method practice questions

Question 1Structured · 4 marks

Consider the differential equation dydx = x − 0.5y, with y = 2 when x = 0.

Use Euler’s method with step length 0.2 to estimate y when x = 0.8.

[4]
Show answers and mark scheme
PartAnswer and marking pointsMarks
1.54
use of Euler’s formula (M1)
y1 = 1.80 (A1)
y2 = 1.66 (A1)
y ≈ 1.54 A1
4
Question 2Structured · 5 marks

The rate of growth of a population P is proportional to P, so that dPdt = kP. Initially P = 500, and after 20 years P = 2477.

(a)

By solving the differential equation, show that P = 500ekt.

[3]
(b)

Find the value of k.

[2]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)shown
separating variables: ∫1PdP = ∫k dt M1
ln P = kt + c A1
using P(0) = 500 AG A1
3
(b)0.0800
2477 = 500e20k (M1)
k = 0.0800 A1
2
Question 3Structured · 4 marks

Consider the differential equation dydx = e−x + y, with y = 2 when x = 0.

Use Euler’s method with step length 0.25 to estimate y when x = 1.

[4]
Show answers and mark scheme
PartAnswer and marking pointsMarks
5.98
use of Euler’s formula (M1)
y1 = 2.75 (A1)
y2 = 3.63 (A1)
y ≈ 5.98 A1
4
Question 4Structured · 5 marks

The rate of growth of a population P is proportional to P, so that dPdt = kP. Initially P = 1200, and after 20 years P = 3262.

(a)

By solving the differential equation, show that P = 1200ekt.

[3]
(b)

Find the value of k.

[2]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)shown
separating variables: ∫1PdP = ∫k dt M1
ln P = kt + c A1
using P(0) = 1200 AG A1
3
(b)0.0500
3262 = 1200e20k (M1)
k = 0.0500 A1
2
Question 5Structured · 4 marks

Consider the differential equation dydx = xy + 1, with y = 2 when x = 0.

Use Euler’s method with step length 0.1 to estimate y when x = 0.4.

[4]
Show answers and mark scheme
PartAnswer and marking pointsMarks
2.43
use of Euler’s formula (M1)
y1 = 2.10 (A1)
y2 = 2.20 (A1)
y ≈ 2.43 A1
4
Question 6Structured · 5 marks

The rate of growth of a population P is proportional to P, so that dPdt = kP. Initially P = 3000, and after 20 years P = 8155.

(a)

By solving the differential equation, show that P = 3000ekt.

[3]
(b)

Find the value of k.

[2]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)shown
separating variables: ∫1PdP = ∫k dt M1
ln P = kt + c A1
using P(0) = 3000 AG A1
3
(b)0.0500
8155 = 3000e20k (M1)
k = 0.0500 A1
2

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Original IB-style practice questions written for mentorriyaz.in. These are not IB past paper questions, and this site is not affiliated with or endorsed by the International Baccalaureate Organization. Updated 2026-11-04. Paper generator · mentorriyaz.in