SOLUTION: HI. This expression is suppose to wrote in a + bi form. I am having some trouble solving it. It's 5i^3/2(square root -4). Thank you very much.

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson  -> Lesson -> SOLUTION: HI. This expression is suppose to wrote in a + bi form. I am having some trouble solving it. It's 5i^3/2(square root -4). Thank you very much.      Log On


   

Question 203358This question is from textbook Intermediate Algebra
: HI. This expression is suppose to wrote in a + bi form. I am having some trouble solving it. It's 5i^3/2(square root -4). Thank you very much. This question is from textbook Intermediate Algebra

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
5i^3/2(square root -4).
:
%285i%5E3%29%2F%282sqrt%28-4%29%29
:
i^3 = i^2 * i; i^2 = -1, therefore -1*i = -i
we have
%28-5i%29%2F%282sqrt%28-4%29%29
;
Extract Square root of neg 1 from the denominator
%28-5i%29%2F%282i%2Asqrt%284%29%29
:
%28-5i%29%2F%282i%2A2%29
:
%28-5i%29%2F%284i%29
Cancel i
%28-5%29%2F4%29 = -1.25
:
You have to write it: -1.25 + 0i