## Excel in math and science

### Master concepts by solving fun, challenging problems.

## It's hard to learn from lectures and videos

### Learn more effectively through short, conceptual quizzes.

## Our wiki is made for math and science

###
Master advanced concepts through explanations,

examples, and problems from the community.

## Used and loved by 4 million people

###
Learn from a vibrant community of students and enthusiasts,

including olympiad champions, researchers, and professionals.

## Comments

Sort by:

TopNewestHey Ali Akbar, are you an Ismaili? Coz I am. – Akbarali Surani · 3 years, 5 months ago

Log in to reply

yes,\( 0^{2}=0 \) – Tan Li Xuan · 4 years ago

Log in to reply

Yes. A perfect square is any number that is a square of an integer, and since \( 0^2 = 0 \), zero is a perfect square. See http://en.wikipedia.org/wiki/Square_number – Hero P. · 4 years ago

Log in to reply