0
$\begingroup$

Find the function from the following graph below: enter image description here

I can see the graph has roots at -3 and 6 so normally I would plug the points into the form of:

$f(x) = k(x - a)(x - b)(x - c)$

But I am unsure what to do with no y intercept.

$\endgroup$
  • $\begingroup$ I would absolutely love to know why this is voted down $\endgroup$ – dagda1 Mar 6 '16 at 10:16
2
$\begingroup$

You also have a root at $1$, so that gives you $a,b,c$. Then note the point $(3,-12)$. That tells you $f(3)=-12$ Plug that in to find $k$

$\endgroup$
  • $\begingroup$ spot on, thanks $\endgroup$ – dagda1 Mar 6 '16 at 16:58
0
$\begingroup$

Use the root at x=1 also. Differentiate (for minimum) to get second degree and plug in $ x=3, y=-12$ to determine $k.$

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.