Question

The number of terms in the expansion of (x^2-2+1/x^2)^6 is?​

Answer 1

Answer:

S=(1+5

2

x)

9

+(1−5

2

x)

9

Let k=5

2

Then the above binomial expansion changes to

S=(1+k)

9

+(1−k)

9

=[1+

9

C

1

k+

9

C

2

k

2

+...

9

C

9

k

9

]+[1−

9

C

1

k+

9

C

2

k

2

−

9

C

3

k

3

...−

9

C

9

k

9

]

=2[1+

9

C

2

k

2

+

9

C

4

k

4

+

9

C

6

k

6

+

9

C

8

k

8

]

Hence in total 5 terms will be there.