5.7.1 – Complex Numbers
We used the method of square roots to solve specific types of quadratics Only used when we had problems such as x 2 – 16 = 0 In all cases, we were taking the square roots of positive numbers
Negative Roots But, sometimes we may encounter problems such as; x = 0 Yields the square root of a negative number Is this possible?
Imaginary Number i To help us deal with this problem, we introduce the imaginary unit i Square Roots of Negative Number Properties 1) If r is a positive real number, then √-r = i √r Example; √-7 = i √7 2) i 2 = -1
Example. Solve the equation 7x 2 = -49
Example. Solve the equation 3x = -4
Example. Solve the equation 4x = -12
Try these 3 problems together. Make sure to note what kind of unit you will need. 1) 5x 2 – 10 = 15 2) -6x 2 = 600 3) 2x = -10
Assignment Pg all, odd