Zaymiey

📐 Mathematics  ·  Binomial Theorem  ·  JEE

Which term in (x + a)ⁿ contains b = a<sup>n</sup>?

Answer: Last term T(n+1).

  • A First term T₁
  • B Middle term
  • C Last term T(n+1)
  • D Second term T₂

Correct answer: C. Last term T(n+1)

Explanation: The last term T(n+1) = nCn x a<sup>n</sup> = a<sup>n.</sup> It contains b (= a here) to the power n.

Pascal's Triangle: Binomial Coefficients11112113311464115101051n=0n=1n=2n=3n=4n=5Each entry = sum of the two entries diagonally above it (Pascal's identity); row n gives nC0...nCn

Row n of Pascal's triangle gives the coefficients nC0, nC1, ..., nCn for the expansion of (a+b)ⁿ; each number is the sum of the two numbers diagonally above it, a direct visual proof of the identity nCr = (n-1)C(r-1) + (n-1)Cr.

Concept context

Expansion of (a+b) n , general term, middle term, binomial coefficients, and greatest term

Read the full Binomial Theorem notes →