What "imaginary" number is defined as the square root of -1?

More Questions:

What is the name of the weak alcoholic cider that is made from the solid remains of the pressed apples??

What country is home to Volvo?

What is the lowest hand that beats a straight in Poker?

Who wrote the 1955 controversial novel "Lolita"?

What author created the character of Tom Robinson?

Margaret Munnerlyn Mitchell, author of the book "Gone with the Wind', was born in what city?

In what country would you find the mouths of the Yukon river?

Cheetahs are native to what two continents?

What athlete had a part in the movie "Steel"?

What were Wilma Flintstone and Betty Rubble's maiden names?

What sport is the focus of the movie "Days of Thunder"?

What sitcom star’s parents were named Morty and Helen on his TV show?

On July 4, 1776, how many English colonies proclaimed a Declaration of Independence?

How is the number 20 written with Roman numerals?

What TV network was home to the TV show "Gunsmoke"?