IMAGINARY AND COMPLEX NUMBERSHigher Concepts of MathematicsComplexNumbersComplex numbers are numbers which consist of a real part and an imaginary part. The solutionof some quadratic and higher degree equations results in complex numbers. For example, theroots of the quadratic equation, x2 - 4x + 13 = 0, are complex numbers. Using the quadraticformula yields two complex numbers as roots.x b b24ac2ax 4 16 522x 4 362x 4 6i2x 2 3iThe two roots are 2 + 3i and 2 - 3i; they are both complex numbers. 2 is the real part; +3i and -3i are the imaginary parts. The general form of a complex number is a + bi, in which "a"represents the real part and "bi" represents the imaginary part.Complex numbers are added, subtracted, multiplied, and divided like algebraic binomials. Thus,the sum of the two complex numbers, 7 + 5i and 2 + 3i is 9 + 8i, and 7 + 5i minus 2 + 3i, is5 + 2i. Similarly, the product of 7 + 5i and 2 + 3i is 14 + 31i +15i2. But i2 equals -1. Thus,the product is 14 + 31i + 15(-1) which equals -1 + 31i.Example 1:Combine the following complex numbers:(4 + 3i) + (8 - 2i) - (7 + 3i) =Solution:(4 + 3i) + (8 - 2i) - (7 + 3i) = (4 + 8 - 7) + (3 - 2 - 3)i= 5 - 2iMA-05 Page 14Rev. 0
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