Algebra
posted by Lee on .
Will you explain the concept of "i" in algebra?
Problem: 4+2i/42i

i = sqrt (1)
so i^2 = sqrt (1)(sqrt(1) = 1
(4+2i)/(42i)
to get rid of i in the denominator multiply top and bottom by the "comlex conjugate of (42i) which is (4+2i)
Rule: conjugate of (abi) is (a+bi)
(4+2i)(4+2i)

(42i)(4+2i)
16 + 16 i +4 i^2
=
(16  2 i^2)
but we all know that i^2 = 1 so
12 + 16 i

18
or
6 + 8 i

9