The quadratic formula that wants me to fail uni

[Poisonedkitten]

I have an assessment due tomorrow and would really appreciate some help. For the life of me I just can’t figure out how to do this darn equation. I don’t necessarily need exact working out, but a point in the right direction would be greatly appreciated.

I’ve created a standard curve based on a bunch of data points curated in our lab (I can add the data points if you need them). I’ve created a polynomial trend line based on these points that has the equation y=-2E-07x^2+0.0015x (the professor said that I’ve done this correctly). Now I have a patients Y data (2.257), but need to show my working out to find their X (should be in the 2000’s range based off my other data). What equation would I need to do to get the answer I’m looking for ? I’ve attempted solving it like a normal quadratic formula, as that was a hint on the report sheet, but I just can’t seem to get it right.

Thankyou in advance for the help, please let me know if you need anymore info

 

[BigBeachBanana]

I have an assessment due tomorrow and would really appreciate some help. For the life of me I just can’t figure out how to do this darn equation. I don’t necessarily need exact working out, but a point in the right direction would be greatly appreciated.

I’ve created a standard curve based on a bunch of data points curated in our lab (I can add the data points if you need them). I’ve created a polynomial trend line based on these points that has the equation y=-2E-07x^2+0.0015x (the professor said that I’ve done this correctly). Now I have a patients Y data (2.257), but need to show my working out to find their X (should be in the 2000’s range based off my other data). What equation would I need to do to get the answer I’m looking for ? I’ve attempted solving it like a normal quadratic formula, as that was a hint on the report sheet, but I just can’t seem to get it right.

Thankyou in advance for the help, please let me know if you need anymore info

I don't know what you mean by "solving it like a normal quadratic formula". How do you normally solve a quadratic? Please share your work.
Perhaps this might help but not necessary.
[math]2.257=(-2\times 10^{-7})x^2+0.0015x\\ \frac{2257}{1000}= -\frac{x^2}{5000000} + \frac{3x}{2000}[/math]