I'm a little confused
f(x) = x^2  4x
I know that gives the equations of:
x^2  4x and
x^2 + 4x
and you can differentiate them, but which equation corresponds to which part of the graph?
Thanks in advance
Printable View
I'm a little confused
f(x) = x^2  4x
I know that gives the equations of:
x^2  4x and
x^2 + 4x
and you can differentiate them, but which equation corresponds to which part of the graph?
Thanks in advance
When $\displaystyle x\ge 0$:Quote:
Originally Posted by freswood
$\displaystyle x^2  4x=x^24x$.
When $\displaystyle x\le 0$:
$\displaystyle x^2  4x=x^2+4x$.
As a reality check you can always try plugging in numbers and seeing what
you get.
RonL
Hello, freswood!
This is equivalent to the piecewise function: $\displaystyle f(x)\:=\:\left\{\begin{array}{cc} x^2  4x & x \geq 0 \\ x^2 + 4x & x < 0\end{array}$Quote:
Find the derivtive of: $\displaystyle f(x) \:= \:x^2  4x$
Differentiate them for both cases.
You can check your results against the graph.
Code:
*  *

*  *
  *      *      *  
4 * *  * * 4
* *  * *

differention of x=x/xQuote:
Originally Posted by Soroban
where x is not equal to 0
Thanks! :)
What confused me is that for something like x^2  4x one applies to y>0 and the other to y < 0.
as in x < 0 U x > 4
and 0<x<4
Can anyone explain the difference between the two?