Question

-3/5_-1/3 optio 1 < 2 > 3 = 4 none ​

Answer 1

Answer:

uses ahha auhs auav Uav ja has. sjsv sj s

Step-by-step explanation:

zvvz

d s

d she

w

wvevkw. s s

so

Answer 2

The given series is,

1×2

1

+

2×3

1

+

3×4

1

+...

nth term,a

n

=

n(n+1)

1

=

n

1

−

n+1

1

,(by partial fractions)

∴a

1

=

1

1

−

2

1

a

2

=

2

1

−

3

1

a

3

=

3

1

−

4

1

...

a

n

=

n

1

−

n+1

1

Adding the above terms columnwise, we obtain

a

1

+a

2

+...+a

n

=[

1

1

+

2

1

+

3

1

+...

n

1

]−[

2

1

+

3

1

+

4

1

+...

n+1

1

]

∴S

n

=1−

n+1

1

=

n+1

n+1−1

=

n+1

n