Calculus problem S(n)=1^2+3^2+5^2+...+(2n-1)^2 ?

Evaluate the limit without using hopital rule or taylor series.

A square has 36 sub-squares in it. How to Number each sub squares from 1 to 36, to make the sum of vertical, the sum of horizontal, and the sum of cross line are the same .Describe in general if possible.

Find the value: P=sin(1⁰)sin(3⁰)sin(5⁰)...sin(89⁰) ?

If f(n)=a^n+b^n+c^n   and f(1)=1,f(2)=2,f(3)=3 ,n=1,2,3,.... Find f(5) ?