SOLUTION: Hello. Please and I mean Please, help me know how to find the y value in a parabola. The y value should either be the highest or the lowest point in a positive or negative curved

Algebra.Com
Question 148665: Hello. Please and I mean Please, help me know how to find the y value in a parabola. The y value should either be the highest or the lowest point in a positive or negative curved u. Thank you very much for your time in helping me solve this question.
Answer by Edwin McCravy(20054)   (Show Source): You can put this solution on YOUR website!
Hello. Please and I mean Please, help me know how to find the y value in a parabola. The y value should either be the highest or the lowest point in a positive or negative curved u. Thank you very much for your time in helping me solve this question.

The formula for the vertex of a parabola, which
is the highest or lowest point, whose equation is:



First we calculate the discriminant

.

then the vertex is

(, ) 

Example:

For the parabola 



We can find a few points by selecting
arbitrary values for x, substituting
and finding the y-values.

For example, if we substitute 
into






So we have the point (-1,5)

We can find others the same way.

I found (-3,-7), (-1,5), (0,8), (3,5), and (5,-7).

Let's plot those:



We compare this problem:



to



and find , , 

To find the vertex, we first calculate the discriminant

.

then the vertex is

(, ) =

(, ) =

(, ) =

(, ) =

So we plot the vertex at (, )



and sketch in the parabola:



Edwin

RELATED QUESTIONS

Hello, can someone please help me with this problem: Use the properties of exponents to... (answered by MathLover1,Edwin McCravy)
I am given three points on a graph (14,0), (10.5,1), (6.5,3) and am asked to find the... (answered by Edwin McCravy)
I need to find an equation for a line whose points are (3,6) and (5,7). I have found the... (answered by atif.muhammad)
The vertex of this parabola is at (1, 2). When the x-value is 0, the y-value is 0. What... (answered by josgarithmetic,Theo,MathTherapy)
For the function of the parabola y=2(x-4)^2 +1 I am asked to remove the parantheses and... (answered by tutorcecilia)
Could you please help me with this problem? I am given the function f(x)= x^2 + 2x + 6... (answered by solver91311,Theo)
Please help me find the exact value of the shortest distance from the origin to each... (answered by scott8148)
Hello, I'm to find the third roots of 343i written in polar form with arguments in... (answered by Alan3354)