Math Help: Solve Quadratic Function Intercepting X-Axis

[ohlhauc1]

Hey! My friend asked me to help him solve this math problem, but I could only get so far to say the x-value is (1,0). Could you please show me how to do the problem? Thanks.

It is:

If a quadratci function intercepts the x-axis at (-2,0) and (4,0) and also goes through the point (7,74), what is its equation in transformational form?

YOU ARE NOT ALLOWED TO USE QUADRATIC REGRESSION OR THE QUADRATIC FORMULA!

The form for transformational form if you do not know is: a(y+k)=(x+h)^2

 

[quasar987]

If I just plug the values in the coordinates we know in the transformational form, I can isolate all 3 unknowns. Or am I missing something?

 

[ohlhauc1]

How would you do that? I do not think it is possible.

 

[quasar987]

1) ak = (-2+h)^2

2) ak = (4+h)^2

1 and 2 combined gives (-2+h)^2 = (4+h)^2, which allows you to find h.

Now that you know h, you can get summon back 1) or 2) to get an expression of k in terms of a. Rewrite a(y+k)=(x+h)^2 by writing k in terms of a and plug the last coordinate.