How would you find the vertex of a parabola using Algebra2/Pre-Calc? (two methods) Using Calc? (one method)?

Answer 1

ON a TI-84 isn't sumthin like calc(button at the top under the screen) and then max or min depending on you're parabola and then showing a right and left bound then press enter...?...Since my thingy has been better restated i feel the need to tell all of you under me to...!!!SEX TEH MONEKEH!!!!!!!!!!!!!!^_^

Answer 2

1) Complete the square so that the equation is in the form

y = a(x-h)^2 + k, then the vertex is at (h,k) and opens up if a>0 and down if a<0

2) By trial and error find two values of x that give the same y value. Then the x value half way between these two xs is the x-coordinate of the vertex.

3) Find the derivative of y=f(x) and the value of x that makes it zero. That is the x-coordiante of the vertex.

4) You can also memorize that the vertex is at x = -b/2a

Answer 3

You will want to use one strategy when the function is given in vertex form y=a(x-h) squared + k. The reason this is called the vertex form is because the vertex is at the point (h, k). Notice that the value of h is the opposite of what it is in the function, but the value of k has the same sign. So when a function is already presented in this form, the vertex is found simply by looking at the numbers in the function.

You will want to use a different strategy when the function is given in standard form y=ax squared + bx + c. You can either use a formula or manipulate the function into vertex form.

Answer 4

The bertex of a parabola.. to find the x of the vertex is -b/2a
whatever you get as an answer, you put that number in for all the x's in the equation.. what ever the y equals is your y for the vertex

Answer 5

Using the calculator graph the function in the y.
Then hit graph. Once you get the graph hit calc. and then press max if the parabola opens down and min if it opens up. Then when it says left bound select any point on the left side of the parabola and when it says right bound select any point on the right side and it will show you the vertex.

Answer 6

if the equation is ax^2 + bx + c, the formula for the vertex is -b/2a. So if you equation was 4x^2 + 6x + 10, the vertex is -(6)/2(4) which equals -6/8, which can be simplified to -3/4.

Answer 7

Well....The truth?
I wouldn't.
I wouldn't want to.
I don't want to know or see any reason for knowing.
But that really isn't the answer you want.
So...
I suppose, instead of using Calc, I would use a Calculator.

Answer 8

If you use calculus, set f'(x)=0 and solve for x. Find y using that x.

Answer 9

Set the derivative is equal to zero.

Answer 10

well can't you just look at the data and graph?