SOLUTION: I have one more problem that I need help in solving....I hope someone can help me. Thank you for your time and for all your help! y=x^2+4x+5 Please include: a) opens up, dow

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: I have one more problem that I need help in solving....I hope someone can help me. Thank you for your time and for all your help! y=x^2+4x+5 Please include: a) opens up, dow      Log On


   



Question 43904This question is from textbook College Algebra
: I have one more problem that I need help in solving....I hope someone can help me. Thank you for your time and for all your help!
y=x^2+4x+5
Please include:
a) opens up, down, right or left
b)vertex
c) axis of symmetry
d) X-intercept
e) y-intercept
f)graph
Thanks a bunch again! smccollough1
This question is from textbook College Algebra

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
y=x^2+4x+5
Write in vertex form by completing the square, as follows:
x^2+4x=y-5
x^2+4x+4=y-5+4
(x+2)^2=y-1
Please include:
a) opens up, down, right or left
Has the form y=+x^2 s]o it opens up.
b)vertex
vertex = (-2,1)
c) axis of symmetry
vertical line through the vertex: x=-2
d) X-intercept
Let y=0 and solve for x in original equation:
x^2+4x+5=0
x=[-4+sqrt(16-20)]/2; discriminant is negative so no x intercepts.
e) y-intercept
Let x=0 in original equation: y=5
f)graph
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B4x%2B5+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%284%29%5E2-4%2A1%2A5=-4.

The discriminant -4 is less than zero. That means that there are no solutions among real numbers.

If you are a student of advanced school algebra and are aware about imaginary numbers, read on.


In the field of imaginary numbers, the square root of -4 is + or - sqrt%28+4%29+=+2.

The solution is x%5B12%5D+=+%28-4%2B-+i%2Asqrt%28+-4+%29%29%2F2%5C1+=++%28-4%2B-+i%2A2%29%2F2%5C1+

Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B4%2Ax%2B5+%29

Cheers,
stan H.