Week 8 Practice Assignment
Mathematics I
Multiple Select Questions (MSQ) and Matching
Question 1 (Matching)
Given:
- Column A: Functions (i) $ f(x) = x e^x $, (ii) $ f(x) = e^{-2x} - 1 $, (iii) $ f(x) = e^x - 1 $
- Column B: Tangent equations (a) $ y = -2x $, (b) $ y = x $, (c) $ y = 0 $
- Column C: Figure numbers (1, 2, 3)
Solution:
- Option 1: (i) â (b) â 3
- Function: $ f(x) = x e^x $
- Tangent at 0: $ f’(x) = (1 + x)e^x $, $ f’(0) = 1 $, tangent $ y = x $
- Figure: 3
- Option 2: (ii) â (a) â 1
- Function: $ f(x) = e^{-2x} - 1 $
- Tangent at 0: $ f’(x) = -2e^{-2x} $, $ f’(0) = -2 $, tangent $ y = -2x $
- Figure: 1
- Option 3: (iii) â (c) â 2
- Function: $ f(x) = e^x - 1 $
- Tangent at 0: $ f’(x) = e^x $, $ f’(0) = 1 $, but the tangent is not given as $ y = x $ here; the solution suggests $ y = 0 $ is incorrect for this function, but as per the matching, (iii) â (c) â 2 is given.
- Option 4: (iii) â (b) â 3
- Not correct as per function and tangent.
- Option 5: (ii) â (a) â 1
- Repeat of correct option above.
- Option 6: (i) â (a) â 1
- Incorrect.
Summary: Correct matches are:
- (i) $ x e^x $ â (b) $ y = x $ â 3
- (ii) $ e^{-2x} - 1 $ â (a) $ y = -2x $ â 1
- (iii) $ e^x - 1 $ â (c) $ y = 0 $ â 2 (though this is not correct mathematically, it is the match given in the solution for the assignment)
Question 2 (Continuity and Limits)
Statement: Consider $ f(x) = e^x - 1 $ and $ g(x) = x $.
Options:
- **(f + g)(x) = e^x - 1 + x$$
- Is (f + g)(x) continuous at $ x = 0 $?
Solution:
- LHL: $\lim_{x \to 0^-} (e^x - 1 + x) = 0$
- RHL: $\lim_{x \to 0^+} (e^x - 1 + x) = 0$
- Value at 0: $(f + g)(0) = 0$
- Conclusion: $(f + g)(x)$ is continuous at $ x = 0 $1.
Question 3 (Limit of Product)
Statement: Find $\lim_{x \to 0} f(x)g(x)$, where $ f(x) = e^x - 1 $, $ g(x) = x $.
Solution:
- $\lim_{x \to 0} (e^x - 1)(x) = 0$
- Answer: $0$
Numerical Answer Type (NAT)
Question 1
Statement: Let $ f $ be a differentiable function at $ x = 1 $. The tangent line to the curve represented by the function $ f $ at the point $(1, 1)$ passes through the point $(2, 2)$. What will be the value of $ f’(1) $?
Solution:
- Slope of tangent: $\frac{2 - 1}{2 - 1} = 1$
- Answer: $f’(1) = 1$1
Question 2
Statement: Let $ f: \mathbb{R} \to \mathbb{R} $ be defined by $ f(x) = x^2 $ and $ g: \mathbb{R} \to \mathbb{R} $ be defined by $ g(x) = x - 5 $. Find the value of $(fg)’(1) - (f \circ g)’(1)$, where $ fg(x) = f(x)g(x) $ and $ f \circ g(x) = f(g(x)) $.
Solution:
- Product rule: $(fg)(x) = x^2(x - 5) = x^3 - 5x^2$
- $(fg)’(x) = 3x^2 - 10x$
- $(fg)’(1) = 3(1)^2 - 10(1) = -7$
- Composition rule: $(f \circ g)(x) = (x - 5)^2$
- $(f \circ g)’(x) = 2(x - 5)$
- $(f \circ g)’(1) = 2(1 - 5) = -8$
- Difference: $-7 - (-8) = 1$
- Answer: $1$1
Summary Table
Question Type | Description | Solution/Answer |
---|---|---|
MSQ/Matching | Match function, tangent, figure | (i) â (b) â 3, (ii) â (a) â 1, (iii) â (c) â 2 |
Continuity | $f+g$ at $x=0$ | Continuous, value = 0 |
Limit | $\lim_{x \to 0} f(x)g(x)$ | 0 |
NAT | $f’(1)$ for tangent | 1 |
NAT | $(fg)’(1) - (f \circ g)’(1)$ | 1 |
Note: The above is based on the available content from the Week 8 Practice Assignment Solution PDF1. If your PDF contains additional or different questions, please upload or specify further details. The second source2 refers to a Computational Thinking assignment, not the mathematics PDF, and is not included in this summary.
https://www.studocu.com/in/document/indian-institute-of-technology-madras/iitm-online-degree-data-science-and-programming/week-8-practice-assignment-solution/99227605 ↩︎ ↩︎ ↩︎ ↩︎
https://www.studocu.com/in/document/indian-institute-of-technology-madras/computational-thinking/ct-week-8-ga-ct-graded-assignment-week-8/63065998 ↩︎