If 112+122+132+⋯ upto ∞=π26, then value of 112+132+152+⋯up to ∞ is
π24
π26
π28
π212
We have 112+132+152+⋯ upto ∞ =112+122+132+142+152+162⋯ upto ∞
−1221+122+132+⋯=π26−14π26=π28