Class CBSE Class 12 Mathematics Definite Integrals Q #631
KNOWLEDGE BASED
UNDERSTAND
1 Marks 2024 AISSCE(Board Exam) MCQ SINGLE
\(\int_{-a}^{a}f(x)dx=0,\) if :
(A) \(f(-x)=f(x)\)
(B) \(f(-x)=-f(x)\)
(C) \(f(a-x)=f(x)\)
(D) \(f(a-x)=-f(x)\)

AI Tutor Explanation

Powered by Gemini

Step-by-Step Solution

  1. Recall the properties of definite integrals: Specifically, the property related to even and odd functions integrated over symmetric intervals.
  2. Consider the case when f(x) is an odd function: An odd function satisfies the condition \(f(-x) = -f(x)\). The integral of an odd function over a symmetric interval \([-a, a]\) is zero. That is, \(\int_{-a}^{a}f(x)dx = 0\) if \(f(-x) = -f(x)\).
  3. Consider the case when f(x) is an even function: An even function satisfies the condition \(f(-x) = f(x)\). The integral of an even function over a symmetric interval \([-a, a]\) is twice the integral from 0 to a. That is, \(\int_{-a}^{a}f(x)dx = 2\int_{0}^{a}f(x)dx\) if \(f(-x) = f(x)\). This is not equal to zero unless the integral from 0 to a is zero.
  4. Analyze the other options: Options (C) and (D) involve the property \(f(a-x)\), which relates to symmetry about the line \(x = a/2\), and doesn't directly imply that the integral from -a to a is zero.
  5. Conclusion: The correct condition for \(\int_{-a}^{a}f(x)dx = 0\) is when \(f(-x) = -f(x)\), which means f(x) is an odd function.

Correct Answer: f(-x)=-f(x)

AI Suggestion: Option B

AI generated content. Review strictly for academic accuracy.

Pedagogical Audit
Bloom's Analysis: This is an UNDERSTAND question because it requires students to recall and explain the properties of definite integrals, specifically how symmetry affects the integral's value.
Knowledge Dimension: CONCEPTUAL
Justification: The question tests the understanding of concepts related to definite integrals and properties of even and odd functions. It requires the student to relate the symmetry of a function to the value of its definite integral over a symmetric interval.
Syllabus Audit: In the context of CBSE Class 12, this is classified as KNOWLEDGE. The question directly assesses the knowledge of properties of definite integrals as covered in the textbook.