Math 1310 Class Notes – Section 2.4, Page 1 of 6 Math 1310 Section 2.4 An Introduction to Complex Numbers A complex number is a number that can be written in the form biawhere aand bare real numbers and .12-=iWe call the number athe real part and we call the number b the imaginary part. If a= 0, the complex number is called a pure imaginary number. Any real number can be written as a complex number with b= 0. •First, you’ll need to be able to classify numbers as real, complex or both. Example 1: Identify each of these numbers as real, complex or both: a. i24-b. 7 c. 36-d. 5 •Identify the real part and the imaginary part Example 2: Write in the form biaand state the real part and the imaginary part. a. 274ib. 95--c.12
Math 1310 Class Notes – Section 2.4, Page 2 of 6 Next, you’ll need to be able to find various powers of i. You’ll need to know these 4 powers: i11*1**1*1224232=--==-=-==-=iiiiiiiiiFor other powers of i, divide the exponent by 4 and find the remainder. Your answer will be iraised to the remainder power.