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Unit 4Radicals. Complex numbers. Complex/Imaginary Numbers. WHAT IS?. There is no real number whose square is -25 so we have to use an imaginary number. WHY?. “i” is an imaginary number. “i” is equal to the square root of -1.
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Unit 4Radicals Complex numbers
Complex/Imaginary Numbers • WHAT IS? There is no real number whose square is -25 so we have to use an imaginary number WHY? “i” is an imaginary number. “i” is equal to the square root of -1 BASICALLY: any time you see a negative under a SQUARE ROOT an “i” gets pulled out.
Simplifying Radicals with Imaginary Numbers • ALWAYS pull the “i” out first before multiplying together.
Adding & Subtracting Complex Numbers • A complex number is a number with “i” in it. • Complex numbers can be written in the form : Imaginary part Real part To add or subtract complex numbers combine the real parts and combine the imaginary parts separately.
Multiplying Complex Numbers • You multiply complex numbers like you would binomials. (Double Distribute, Box, FOIL…etc)
Dividing Complex Numbers • Remember that we don’t want to leave a radical in the denominator. • To simplify a quotient, multiply by the conjugate of the denominator. • Conjugate – change only the middle sign CONJUGATE = CONJUGATE = CONJUGATE =
Rationalize the Denominator Simplify Imaginary # song
i Since “i” raised to a power follows a pattern you can easily find the answer by dividing the exponent by 4 and using the remainder to simplify. 4 goes into 12, 3 times with a remainder of zero. 4 goes into 22, 5 times with a remainder of 2 What about higher exponents? 4-7? 4 goes into 33, 8 times with a remainder of 1