SOLUTION: Hello, I a having a hard time with this complex numbers problem. Any help is greatly appreciated! The point (-4+bi)has been plotted on the complex plane ad r=8. If 0°≤&#9

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson -> SOLUTION: Hello, I a having a hard time with this complex numbers problem. Any help is greatly appreciated! The point (-4+bi)has been plotted on the complex plane ad r=8. If 0°≤&#9      Log On


   

Question 395837: Hello, I a having a hard time with this complex numbers problem. Any help is greatly appreciated!
The point (-4+bi)has been plotted on the complex plane ad r=8. If 0°≤θ≤180° find the value of b. Leave your answer as a radical.
θ= Theta
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Hint: Recall that the number a%2Bbi has the modulus r=sqrt%28a%5E2%2Bb%5E2%29. In your case, a=-4 and r=8. So 8=sqrt%28%28-4%29%5E2%2Bb%5E2%29