Let 
If 
, find the value of k.
Let 
→ 
or, 
or , h → 0
Putting this in the original sum,
[ Applying formula 
]
= -k × 1
= -k
It is given that 
∴ -k = 3
→ k = -3
1
Let
If , find the value of k.
Let
→
or,
or , h → 0
Putting this in the original sum,
[ Applying formula ]
= -k × 1
= -k
It is given that
∴ -k = 3
→ k = -3