View more at http://www.MathTutorDVD.com. In this lesson, we will explore the concept of the imaginary number in algebra. We will discuss that for each new type of equation in algebra, a new type of number was needed to solve the equation. For equations involving square roots, we need the concept of the imaginary number "i", which is the square root of negative 1. In parallel with this, we know that i^2 is equal to -1. We explore how to take the square root of negative numbers using imaginary numbers and discuss their significance.