You can have legends in golf and tennis. What about mathematics? Yes you can also have legends in mathematics.
Leornard Euler is one of them.

His name is pronounced 'Oil-er' not 'you-ler'. Go ahead, make oil related puns. He was born in 1707 and died in 1783. During his lifetime, his work has been beneficial to the mathematical community. For those who are knowledgeable about calculus, you should have touched on a few of his theorems. You should of heard of 'e', a constant discovered by... Leonard Euler. This was discovered when Euler was looking at logarithmic graphs. You may of heard of the harmonic numbers. If not, they are: 1 + 1/2 + 1/3 + 1/4 ... 1/n (you stop when you reach 1/n if your repeating it n times). Euler figured out another constant that links these which is written as y. Because n-1th harmonic number /nth harmonic number gets closer to y as you progress.
In the 1740's he lost sight in his eye. Probably due to a cataract. He later lost his other eye's eyesight. This didn't stop him. He got people to right down his work for him. He even performed a calculation to 50 decimal places to see which of his students was right.

I will conclude with arguably the greatest formula ever discovered from Euler.

e^i(Pi)=-1 Where ^ indicates a power, e is his constant and i is an imaginary number which equals the square root of -1. i assuming that value was his suggestion. It is difficult to explain why the formula is true. I don't understand the proof myself. It is good because it relates to constants with an imaginary number.

I'll leave that open for anyone willing to have a shot.