English

Find the Middle Term in the Expansion Of: (Ii) ( a X + B X ) 12

Advertisements
Advertisements

Question

Find the middle term in the expansion of: 

(ii)  \[\left( \frac{a}{x} + bx \right)^{12}\]

 

Advertisements

Solution

(ii) Here,
n = 12 (Even number)
Therefore, the middle term is the 

\[\left( \frac{n}{2} + 1 \right)th\]   i.e. 7th term
 
\[Now, \]
\[ T_7 = T_{6 + 1} \]
\[ =^{12}{}{C}_6 \left( \frac{a}{x} \right)^{12 - 6} (bx )^6 \]
\[ = ^{12}{}{C}_6 a^6 b^6 \]
\[ = \frac{12 \times 11 \times 10 \times 9 \times 8 \times 7}{6 \times 5 \times 4 \times 3 \times 2} a^6 b^6 \]
\[ = 924 a^6 b^6\]

 

shaalaa.com
  Is there an error in this question or solution?
Chapter 18: Binomial Theorem - Exercise 18.2 [Page 38]

APPEARS IN

R.D. Sharma Mathematics [English] Class 11
Chapter 18 Binomial Theorem
Exercise 18.2 | Q 13.2 | Page 38

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Write the general term in the expansion of (x2 – yx)12, x ≠ 0


Find the 4th term in the expansion of (x – 2y)12 .


Find the 13th term in the expansion of `(9x - 1/(3sqrtx))^18 , x != 0`


The coefficients of the (r – 1)th, rth and (r + 1)th terms in the expansion of (x + 1)n are in the ratio 1:3:5. Find n and r.


Prove that the coefficient of xn in the expansion of (1 + x)2n is twice the coefficient of xn in the expansion of (1 + x)2n–1 .


Find the middle terms in the expansion of: 

(iii) \[\left( 3x - \frac{2}{x^2} \right)^{15}\]

 


Find the middle terms(s) in the expansion of:

(ii)  \[\left( 1 - 2x + x^2 \right)^n\]


Find the middle terms(s) in the expansion of:

(iii)  \[\left( 1 + 3x + 3 x^2 + x^3 \right)^{2n}\]

 


Find the middle terms(s) in the expansion of: 

(vi)  \[\left( \frac{x}{3} + 9y \right)^{10}\]

 


Find the middle terms(s) in the expansion of:

(viii)  \[\left( 2ax - \frac{b}{x^2} \right)^{12}\]

 


Find the term independent of x in the expansion of the expression: 

(i) \[\left( \frac{3}{2} x^2 - \frac{1}{3x} \right)^9\]

 


Find the term independent of x in the expansion of the expression: 

(vi)  \[\left( x - \frac{1}{x^2} \right)^{3n}\]

 


Find the term independent of x in the expansion of the expression: 

(vii)  \[\left( \frac{1}{2} x^{1/3} + x^{- 1/5} \right)^8\]

 


Find the term independent of x in the expansion of the expression: 

(x) \[\left( \frac{3}{2} x^2 - \frac{1}{3x} \right)^6\]

 


If the coefficients of \[\left( 2r + 4 \right)\text{ th and } \left( r - 2 \right)\] th terms in the expansion of  \[\left( 1 + x \right)^{18}\]  are equal, find r.

 
 
 

Prove that the term independent of x in the expansion of \[\left( x + \frac{1}{x} \right)^{2n}\]  is \[\frac{1 \cdot 3 \cdot 5 . . . \left( 2n - 1 \right)}{n!} . 2^n .\]

 
 

In the expansion of (1 + x)n the binomial coefficients of three consecutive terms are respectively 220, 495 and 792, find the value of n.


If in the expansion of (1 + x)n, the coefficients of three consecutive terms are 56, 70 and 56, then find n and the position of the terms of these coefficients.


Write the middle term in the expansion of `((2x^2)/3 + 3/(2x)^2)^10`.


Write the middle term in the expansion of  \[\left( x + \frac{1}{x} \right)^{10}\]

 

The number of irrational terms in the expansion of \[\left( 4^{1/5} + 7^{1/10} \right)^{45}\]  is

 

If the term free from x in the expansion of `(sqrt(x) - k/x^2)^10` is 405, find the value of k.


Find the middle term (terms) in the expansion of `(x/a - a/x)^10`


Find the coefficient of `1/x^17` in the expansion of `(x^4 - 1/x^3)^15`


Show that the middle term in the expansion of `(x - 1/x)^(2x)` is `(1 xx 3 xx 5 xx ... (2n - 1))/(n!) xx (-2)^n`


Find the term independent of x in the expansion of (1 + x + 2x3) `(3/2 x^2 - 1/(3x))^9`


In the expansion of `(x^2 - 1/x^2)^16`, the value of constant term is ______.


The position of the term independent of x in the expansion of `(sqrt(x/3) + 3/(2x^2))^10` is ______.


The last two digits of the numbers 3400 are 01.


The coefficient of x256 in the expansion of (1 – x)101(x2 + x + 1)100 is ______.


The number of rational terms in the binomial expansion of `(4^(1/4) + 5^(1/6))^120` is ______.


The sum of the co-efficients of all even degree terms in x in the expansion of `(x + sqrt(x^3 - 1))^6 + (x - sqrt(x^3 - 1))^6, (x > 1)` is equal to ______.


The coefficient of y49 in (y – 1)(y – 3)(y – 5) ...... (y – 99) is ______.


If the coefficient of x10 in the binomial expansion of `(sqrt(x)/5^(1/4) + sqrt(5)/x^(1/3))^60` is 5kl, where l, k ∈ N and l is coprime to 5, then k is equal to ______.


The term independent of x in the expansion of `[(x + 1)/(x^(2/3) - x^(1/3) + 1) - (x - 1)/(x - x^(1/2))]^10`, x ≠ 1 is equal to ______.


The sum of the real values of x for which the middle term in the binomial expansion of `(x^3/3 + 3/x)^8` equals 5670 is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×