Advertisements
Advertisements
Question
Find the 5th term in the expansion of (x – 2y)13.
Advertisements
Solution
General term is tr+1 = nCr xn-r ar
(x – 2y)13 = (x + (-2y))13
Here x is x, a is (-2y) and n = 13
5th term = t5 = t4+1 = 13C4 x13-4 (-2y)4
= 13C4 x9 24 y4
`= (13xx12xx11xx10)/(4xx3xx2xx1)`× 2 × 2 × 2 × 2× x9y4
= 13 × 11 × 10 × 8x9y4
= 13 × 880x9y4
= 11440x9y4
APPEARS IN
RELATED QUESTIONS
Evaluate the following using binomial theorem:
(101)4
Evaluate the following using binomial theorem:
(999)5
Expand the following by using binomial theorem.
`(x + 1/x^2)^6`
Show that the middle term in the expansion of is (1 + x)2n is `(1*3*5...(2n - 1)2^nx^n)/(n!)`
The middle term in the expansion of `(x + 1/x)^10` is
Expand `(2x^2 -3sqrt(1 - x^2))^4 + (2x^2 + 3sqrt(1 - x^2))^4`
Using binomial theorem, indicate which of the following two number is larger: `(1.01)^(1000000)`, 10
Find the last two digits of the number 3600
If n is a positive integer, using Binomial theorem, show that, 9n+1 − 8n − 9 is always divisible by 64
In the binomial expansion of (a + b)n, if the coefficients of the 4th and 13th terms are equal then, find n
