NCERT Class 12 · Ch 7 Exercise 7.10 · Q19
NCERT Class 12 Maths · Chapter 7 Integrals · Exercise 7.10 Question 19
Show ∫₀ᵃf(x)g(x)dx=2∫₀ᵃf(x)dx if f(x)=f(a−x) and g(x)+g(a−x)=4.
💡 Concept Hints
- Identify the domain and the inner and outer functions, or the relevant one-sided limits.
- Apply the appropriate differentiation or limit rule, keep all chain factors, and check exceptional points.
✅ Step-by-Step Solution
Final Answer: The identity holds whenever the indicated integrals exist.
- Let I=∫₀ᵃf(x)g(x)dx. Reflect x↦a−x: I=∫₀ᵃf(a−x)g(a−x)dx=∫₀ᵃf(x)g(a−x)dx.
- Add the two forms: 2I=∫₀ᵃf(x)[g(x)+g(a−x)]dx=4∫₀ᵃf(x)dx. Divide by 2.
Master Chapter 7: Integrals
Practise interactive questions, flashcards, visual mind maps, and timed board tests for Integrals.
← Previous Question
Evaluate \(\int\limits_{0}^{4} \left|{x - 1}\right|\, dx\) using…
Next Question →Evaluate ∫₋π/₂^π/₂(x³+x cos x+tan⁵x+1)dx.
Related Questions in Integrals
Class 12 Integrals · Mcq Single Correct
Evaluate \(\int x^2e^{x^3}\,dx\).
Class 12 Integrals · Mcq Single Correct
Evaluate \(\int e^x(1+x)\sec^2(xe^x)\,dx\) on an interval where defined.
Class 12 Integrals · Mcq Single Correct
Evaluate \(\int e^x(\cos x-\sin x)\,dx\).
Class 12 Integrals · Mcq Single Correct
Evaluate \(\int dx/(\sin^2x\cos^2x)\) on an interval avoiding its poles.
Class 12 Integrals · Mcq Single Correct
If \(\int\frac{3e^x-5e^{-x}}{4e^x+5e^{-x}}dx=ax+b\ln|4e^x+5e^{-x}|+C\), find a,b.
Class 12 Integrals · Mcq Single Correct
Evaluate \(\int_{-1}^{1}|x-2|/(x-2)\,dx\).