Question 34747
SEE ANSWERS BELOW
What does the symbol "i" represent?
IN SHORT FOR YOUR PRESENT PURPOSE YOU MAY TAKE IT AS AN IMAGINARY NUMBER WHICH WHEN MULTIPLIED BY IT SELF GIVES -1....THAT IS i*i=-1.....AS YOU CAN SEE IT IS IMAGINARY SINCE NO REAL NUMBER WHEN MULTIPLIED BY ITSELF GIVES US -1.
Is "12.5555…" a rational or irrational number? Explain.
IT IS RATIONAL BECAUSE IT CAN BE WRITTEN AS 113/9...THAT IS RATIO OF 2 INTEGERS.
Is "2.1273685…" a rational or irrational number? Explain.
ASSUMING THERE IS NO PATTERN IN ITS CONTINUATION,IT IS IRRATIONAL BECAUSE IT CANNOT BE WRITTEN AS P/Q WHERE P AND Q ARE INTEGERS.
Is "548/799" a rational or irrational number? Explain.
IT IS RATIONAL BY DEFINITION  BECAUSE IT IS RATIO OF 2 INTEGERS.
Simplify "(5 + 3i)(5 - 3i)". Is the result real, complex, or both? Explain.
USING (A+B)(A-B)=A^2-B^2....WE GET ANSWER AS 5^2-3^2*i^2...SINCE i^2=-1,WE GET 
ANSWER AS 25-9*(-1)=25+9 = 34..IT IS A REAL NUMBER.