# Absolute(y)

• Apr 26th 2010, 10:07 AM
Schdero
Absolute(y)
Does anyone know a piece of advice, how to draw graphs like

abs(y)=1-x^2?

thanks
• Apr 26th 2010, 11:02 AM
Failure
Quote:

Originally Posted by Schdero
Does anyone know a piece of advice, how to draw graphs like

abs(y)=1-x^2?

thanks

$\displaystyle |y|=1-x^2$ just meas that $\displaystyle y=1-x^2$ or $\displaystyle -y=1-x^2$.

Therefore you can just draw the graph of $\displaystyle y=1-x^2$, and then draw that graph again, but flipped around the x-axis (which changes the sign of the y-coordinates only).
Of course, the resulting figure is not the graph of a function, but it is the graph of a relation (between x and y).
• Apr 26th 2010, 11:09 AM
Amer
Quote:

Originally Posted by Schdero
Does anyone know a piece of advice, how to draw graphs like

abs(y)=1-x^2?

thanks

our function

$\displaystyle \left\{\begin{array}{cc} y=1-x^2 ,&\mbox y\geq 0 \\-y=1-x^2 ,&\mbox y<0 \end{array}\right.$

draw the two functions we have
• Apr 26th 2010, 11:19 AM
Schdero
Thank s to both!