SOLUTION: Determine the nature of the solutions of the equation x2-4=0. A: 1 real solution B: 2 real solutions C: 2 imaginary solutions

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Determine the nature of the solutions of the equation x2-4=0. A: 1 real solution B: 2 real solutions C: 2 imaginary solutions       Log On


   

Question 374363: Determine the nature of the solutions of the equation x2-4=0.
A: 1 real solution
B: 2 real solutions
C: 2 imaginary solutions
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
The fastest way to answer this question uses the discriminant, b%5E2+-+4ac, with the a, b and c coming from ax%5E2%2Bbx%2Bc. If this expression is:
  • zero, then there is one real solution.
  • positive, then there are two real solutions
  • negative, then there are two complex (non-real) solutions

For x%5E2-4 the discriminant is:
%280%29%5E2-4%281%29%28-4%29
which simplifies as follows:
0 - 4(1)(-4)
0 + 16
16
This is positive so there are two real solutions.