Question

Find the term independent of x in the expansion of (x-1/x²)^9.​

Answer 1

Step-by-step explanation:

We know, T

r+1

=

n

C

r

a

n−r

b

r

Applying to the above question, we get

T

r+1

=(−1)

r

9

C

r

x

18−2r

x

−r

=(−1)

r

9

C

r

x

18−3r

...(i)

For term independent of x

18−3r=0

∴r=6

Substituting in (i), we get

T

7

=

9

C

6

=84