Solutions of National Book Foundation, NBF. 

Complex numbers are mathematical entities that consist of both a real part and an imaginary part. They are represented in the form a + bi, where “a” represents the real part and “b” represents the imaginary part, and “i” represents the imaginary unit (√-1).The real part of a complex number represents a quantity that can be measured on the real number line, while the imaginary part represents a multiple of the imaginary unit “i.” The imaginary unit “i” is defined as the square root of -1, and it allows us to work with numbers that have no real square roots.