SOLUTION: How do I add imaginary numbers that are square roots, do I convert first to i then add? Example= sqrt(-9) + sqrt (-36)

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson -> SOLUTION: How do I add imaginary numbers that are square roots, do I convert first to i then add? Example= sqrt(-9) + sqrt (-36)      Log On


   

Question 38541: How do I add imaginary numbers that are square roots, do I convert first to i then add? Example= sqrt(-9) + sqrt (-36)
Found 2 solutions by fractalier, AnlytcPhil:
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
Properly, you pull the i's out first...like this...
sqrt(-9) + sqrt(-36) =
i*sqrt(9) + i*sqrt(36) =
3i + 6i =
9i
You could however, merely evaluate the roots initially as 3i and 6i and then add, but properly it is done as above...

Answer by AnlytcPhil(1806) About Me  (Show Source):
You can put this solution on YOUR website!
   Example: sqrt(-9) + sqrt (-36)
               __    ___ 
              Ö-9 + Ö-36
                _     __
              iÖ9 + iÖ36

             i(3) + i(6)

              3i + 6i

                9i

Edwin
AnlytcPhil@aol.com