SOLUTION: please help me I'm coming up with crazy answer. Determine whether the following equations have a solution or not? Justify your answer. (3)1/2y2 - 4y - 7(3)1/2 = 0 than

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: please help me I'm coming up with crazy answer. Determine whether the following equations have a solution or not? Justify your answer. (3)1/2y2 - 4y - 7(3)1/2 = 0 than      Log On


   

Question 172399This question is from textbook
: please help me I'm coming up with crazy answer.
Determine whether the following equations have a solution or not? Justify your answer.
(3)1/2y2 - 4y - 7(3)1/2 = 0

thank you in advance. This question is from textbook

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Note: %283%29%5E%281%2F2%29=sqrt%283%29


So %283%29%5E%281%2F2%29y%5E2+-+4y+-+7%283%29%5E%281%2F2%29y+=+0 also looks like sqrt%283%29y%5E2+-+4y+-+7sqrt%283%29y+=+0



From sqrt%283%29y%5E2+-+4y+-+7sqrt%283%29y we can see that a=sqrt%283%29, b=-4, and c=7sqrt%283%29


D=b%5E2-4ac Start with the discriminant formula.


D=%28-4%29%5E2-4%28sqrt%283%29%29%28-7sqrt%283%29%29 Plug in a=sqrt%283%29, b=-4, and c=7sqrt%283%29


D=16-4%28sqrt%283%29%29%28-7sqrt%283%29%29 Square -4 to get 16


D=16%2B84 Multiply -4%28sqrt%283%29%29%28-7sqrt%283%29%29 to get %28-4%29%2A%28-7%29%2Asqrt%283%2A3%29=28%2Asqrt%289%29=28%2A3=84


D=100 Add



Since the discriminant is greater than zero, this means that there are two real solutions.