Expert: Ahmed Salami - 10/18/2011

Question
find the sum of two numbers whose sum is 2 and their product is 2

Answer
Hi Simike,
If the numbers are x and y, then we can form the equations;
x + y = 2
and
xy = 2
We can now substitute for y in the second equation from the first to get
x(2 - x) = 2
2x - x² = 2
x² - 2x + 2 = 0
Using the quadratic formula;
x = [2 ± √(2² - 4.1.2)] / 2
x = [2 ± √(-4)] / 2
x = [2 ± 2i] / 2     where i is the imaginary unit √-1
x = 1 ± i

Regards