Finding the fixed point..

Question

I don't quite understand this question.

$f(x)=ax^2+bx+c$, where $a=14,b=−25$ and $c=−7$. There are two fixed points at $x_1$ and $x_2$, where $x_1>x_2$. How to get the value of $x_1$? In two decimal places.

Just click on the link below for my working, I think I got it wrong. Can someone help me on this?

Click on this link for the working

Answer 1

You should not be solving for $$ax^2+bx+c=0$$

You should be solving for $$ax^2+bx+c=x$$

that is the definition of a fixed point.

Answer 2

let $x$ be a fixed point, then $f(x)=x$, solve this equation. Or you can think of a function $g(x)=f(x)-x$ and find the roots