Question

The coefficient of y in the expansion of (y? + c/y)5 is​

Answer 1

Step-by-step explanation:

y

2

+c/y)

5

=

5

C

0

(

y

c

)

0

(y

2

)

5−0

+

5

C

1

(

y

c

)

1

(

y

2

)

5−1

+...+

5

C

5

(

y

c

)

5

(y

2

)

5−5

=

r=0

∑

5

5

C

r

(

y

c

)

r

(y

2

)

5−r

We need cofficinet of y ⇒2(5−r)−r=1

⇒10−3r=1

⇒r=3

So, cofficient of y=

5

C

3

.C

3

=10C

3