In the following expansion, find the indicated term. (x2-4x3)11, 5th term - Mathematics and Statistics

Sum

In the following expansion, find the indicated term.

(x^2 - 4/(x^3))^11, 5th term

Solution

Here, a = x2 , b = -(4)/x^3, n = 11

For 5th term, r = 4

We have, tr+1 = nCr . an–r.br

∴ t5 = ""^11"C"_4(x^2)^(11 - 4).(-(4)/x^3)^4

= (11!)/(4!7!)(x^2)^7.(-(4)/x^3)^4

= (11 xx 10 xx 9 xx 8)/(4 xx 3 xx 2 xx 1) xx x^14 xx 256/x^12

= 330 × 256 × x2

= 84480 x2

∴ 5th term in the expansion of (x^2 - 4/x^3)^11 is 84480 x2

Concept: General Term in Expansion of (a + b)n
Is there an error in this question or solution?

APPEARS IN

Balbharati Mathematics and Statistics 2 (Arts and Science) 11th Standard Maharashtra State Board
Chapter 4 Methods of Induction and Binomial Theorem
Exercise 4.3 | Q 1. (ii) | Page 80