Question

1. Using Binomial Theorem for positive integral index, expand the following
(ii) (y - x)
(iii
x 2
(i) (a + b)
X0
2 x
X​

Answer 1

It is known that the general term T

r+1

which is the (r+1)th term in

the binomial expansion of (a+b)

n

is given by T

r+1

=

n

C

r

a

n−r

b

r

Thus, the general term in the expansion of (x

2

−yx)

12

is

T

r+1

=

12

C

r

(x

2

)

12−x

(−yx)

r

=(−1)

r

12C

r

.x

24−2r

.y

r

.x

r

=(−1)

r

12C

r

.x

24−r

.y

r