The line l:
Intersects the line $f(x) = \sqrt{x^2 +9} - x^2 + 5x$
Is parallel to the line $m: y = 5x-2 $
Find the formula of line l algebraically.
So, I found the derivative of f, which is $ \dfrac{x} {\sqrt{x^2+9}} - 2x+5$, and I know that line l has a slope of 5. So I got to the point $ \dfrac{x} {\sqrt{x^2+9}} - 2x = 0 $, but I don't know how to solve this..