
In ECET 2026 Mathematics, Calculus theorems like Rolle’s Theorem and Mean Value Theorem (MVT) are frequently tested. The Mean Value Theorem is one of the most fundamental results in differential calculus, often used in proofs and problem solving.
📘 Concept Notes – Mean Value Theorem
🔹 Statement of MVT
If:
is continuous on
is differentiable on
Then ∃ at least one point such that:
🔹 Geometric Meaning
- The theorem says: At some point, the tangent to the curve is parallel to the secant line joining
and
.
🔹 Relation with Rolle’s Theorem
- Rolle’s Theorem is a special case of MVT when
.
- Then,
for some
.
⚙️ Key Formula
- General MVT condition:
- Slope of secant line:
- At some
, slope of tangent:
📐 Example
Example 1:
Verify Mean Value Theorem for in
.
- Check conditions:
- Continuous and differentiable (yes).
- Compute slope of secant:
Differentiate:
Solve:
✅ Hence, MVT is satisfied at .
🔟 10 Expected MCQs – ECET 2026
Q1. The Mean Value Theorem requires function to be:
A) Continuous in [a, b]
B) Differentiable in (a, b)
C) Both A & B
D) None
Q2. If , MVT reduces to:
A) Rolle’s Theorem
B) Lagrange’s Theorem
C) Taylor’s Theorem
D) Cauchy’s Theorem
Q3. For on [1, 3], value of c that satisfies MVT is:
A) 1
B) 2
C) 3
D) None
Q4. If on [0, π], then slope of secant line is:
A) 0
B) 1
C) -1
D) None
Q5. Condition NOT required for MVT:
A) Continuity on [a, b]
B) Differentiability on (a, b)
C) f(a) = f(b)
D) None
Q6. For on [1, 2], slope of secant line is:
A) 5
B) 7
C) 9
D) 3
Q7. In MVT, the slope of tangent at c is:
A) Equal to slope of secant
B) Less than slope of secant
C) Greater than slope of secant
D) Independent
Q8. Rolle’s Theorem guarantees existence of:
A) f’(c) = slope of secant
B) f’(c) = 0
C) f(c) = 0
D) None
Q9. For on [1, e], slope of secant line is:
A) 0
B) 1
C) e
D) None
Q10. In MVT, the number of possible c values:
A) Always unique
B) At least one
C) Infinite
D) Zero
✅ Answer Key
Q.No | Answer |
---|---|
Q1 | C |
Q2 | A |
Q3 | B |
Q4 | A |
Q5 | C |
Q6 | B |
Q7 | A |
Q8 | B |
Q9 | B |
Q10 | B |
🧠 Explanations
- Q1 → C: Both conditions required.
- Q2 → A: Special case → Rolle’s Theorem.
- Q3 → B: c = 2 satisfies MVT.
- Q4 → A:
.
- Q5 → C: f(a) = f(b) is for Rolle’s Theorem, not MVT.
- Q6 → B:
.
- Q7 → A: By definition.
- Q8 → B: Rolle’s Theorem ensures f’(c) = 0.
- Q9 → B:
.
- Q10 → B: At least one c exists.
🎯 Why Practice Matters
- MVT and Rolle’s Theorem are repeated exam topics.
- Questions are straightforward: slope, derivative, and verification.
- Practicing ensures quick marks in calculus section.