finding parabola points

[Mr.G.00]

How to calculate additional points in parabola. I have three points and vertex of parabola, need 2 points more in between of three known points.
this parabola is in excel that I received from a friend.
Thanks in advance
edit vertex is not calculated correctly.
it's 5.5 with 2.255

 

[tkhunny]

Looks like an estimation problem. Draw some perpendiculars and give it a best guess.

If you want, you can get Excel to do it form you more precisely.
1) Enter the three points as given.
2) Select the 6 cells and draw a chart.
3) Right click any of the 3 points
4) Pick "Add Trend Line"
5) Pick Polynomial Order 2
6) Pick "Display Equation on Chart".

 

[Dr.Peterson]

How to calculate additional points in parabola. I have three points and vertex of parabola, need 2 points more in between of three known points.
this parabola is in excel that I received from a friend.
Thanks in advance
edit vertex is not calculated correctly.
it's 5.5 with 2.255

If you needed to do this by hand, I'd plug the three given points into y=ax^2+bx+c and solve for a, b, and c. Then you have the equation and can plug in the other values of x.

How did you determine the vertex?

 

[Mr.G.00]

Looks like an estimation problem. Draw some perpendiculars and give it a best guess.

If you want, you can get Excel to do it form you more precisely.
1) Enter the three points as given.
2) Select the 6 cells and draw a chart.
3) Right clock any of the 3 points
4) Pick "Add Trend Line"
5) Pick Polynomial Order 2
6) Pick "Display Equation on Chart".

Thanks for your help. I have managed to find equation and with that to find another points. There is some difference, but for now it is great.
Thanks again.

 

[Mr.G.00]

If you needed to do this by hand, I'd plug the three given points into y=ax^2+bx+c and solve for a, b, and c. Then you have the equation and can plug in the other values of x.

How did you determine the vertex?

When I find time, I will definitely try to calculate it by hand, just to see the difference. Vertex is given through excel where parabola is drawn.
Thanks for the help.

 

[Dr.Peterson]

Vertex is given through excel where parabola is drawn.

I didn't know Excel had a function to find the vertex. I'll have to look it up.