Question

2) Write the first four terms in the expansion

of 1
/(2+)
^4

.​

Answer 1

Answer:

jfhiv xszghygvxvhytsghugdsgu

Answer 2

Answer:

Coefficient of (r+1)th in the expansion of (1+x)

n

is

n

C

r

Given 2nd, 3rd and 4th terms are in A.P

⇒2.

n

C

2

=

n

C

1

+

n

C

3

⇒n(n−1)=n+

6

n(n−1)(n−2)

⇒6(n−1)=6+n

2

−3n+2

⇒n

2

−9n+14=0⇒n=7