If f(x)=ln(2x), then f′(3) equals:
- 1/3
- 2/3
- 1/6
- 3/2
Show answer and explanation
Answer: A. 1/3
f′(x)=1/x; f′(3)=1/3.
Practise 61 real Federal Board questions on Differentiation from 2023 to 2026. See the answer and explanation as soon as you answer.
Differentiation is one of the 14 main chapters in our Federal Board FSC Mathematics question bank (12th class), and about 13% of its real questions come from it. Tayyari Karo has 61 real questions on this chapter from 2023 to 2026; 24 are multiple choice and marked instantly, and the rest are short and long questions with a model answer. By difficulty: 31 medium, 19 hard, 11 easy.
Work through the questions below, then open the explanation for each one. Redo the ones you missed a few days later.
These are real past-paper questions. Think of your answer first, then open the explanation.
If f(x)=ln(2x), then f′(3) equals:
Answer: A. 1/3
f′(x)=1/x; f′(3)=1/3.
d/dx(eˣ+3e^(−3x)) =
Answer: A. eˣ−9e^(−3x)
d/dx(3e^(−3x))=−9e^(−3x).
If (1/x²)dy/dx=3 then solution y(x) of differential equation is:
Answer: A. x³+c
dy=3x²dx ⇒ y=x³+c.
If z=x²+xy+y², then ∂z/∂x is:
Answer: D. 2x+y
Treat y as constant: ∂z/∂x=2x+y.
The degree of the differential equation (d²y/dx²)³+dy/dx=x is:
Answer: A. 3
Power of the highest-order derivative term is 3.
If f(x)=e^(ln(Sinx)), then what is the value of f′(π/2)?
Answer: B. 0
e^(ln(Sinx)) = Sinx, so f′(x)=Cosx, and f′(π/2)=Cos(π/2)=0.
The population of a city grows at a rate proportional to its current population. In 2020, the population was 50,000. In 2025, it became 60,000. (a) Find the growth constant k. (b) Predict the population in 2030.
P=P₀e^(kt); 60000=50000e^(5k) ⇒ e^(5k)=1.2 ⇒ k=(1/5)ln(1.2)
k ≈ 0.0365 per year
At t=10 (year 2030): P=50000e^(10k)=50000(1.2)²=50000(1.44)
P(2030) ≈ 72,000
Differentiate y=sin⁻¹(2x/(1+x²)) w.r.t. x.
Let x=tanθ: 2x/(1+x²)=sin2θ, so y=sin⁻¹(sin2θ)=2θ=2tan⁻¹x
dy/dx = 2/(1+x²)
| Session | Questions |
|---|---|
| 2026 Annual | 13 |
| 2025 1st Annual | 17 |
| 2025 2nd Annual | 16 |
| 2024 Annual | 8 |
| 2023 Annual | 7 |
61 real Federal Board (FBISE) Mathematics questions on Differentiation from 2023 to 2026, for 12th class. Each one shows the session it came from.
No. We could not find an official FBISE marking scheme for these papers, so the answers and explanations are written by Tayyari Karo for practice. Check anything important with your teacher or textbook.
You can start free with no signup. A small set of papers per subject is free, and Premium unlocks the full question bank.