Re: Graphing piecewise functions?


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Re: Graphing piecewise functions?



At 10:56 PM -0400 10/14/98, Charlie Reno wrote:
>On Wed, 14 Oct 1998, Kasper Vibe Grevsen wrote:
>> How do I graph
>>
>>          x^2 for x<0
>> f(x)={
>>          sqrt(x) for x>=0
>>
>> I know you would say y1=(x<0)x^2+(x>=0)sqrt(x) but that does not work
>> because sqrt(x) is undefined for negative x values.
>>
>> I tried graphing y1=(x<0)x^2 and y2=(x>=0)sqrt(x) but it is not very handy
>> and it results in some grim line.
>
>It is great to have a single expression so that you can easily integrate
>from -2 to 2, for example.
>Try
>  y1 = x^2*(x<0) + sqrt(abs(x))*(x>=0)

Or, you could use:

y1 = x^2*(x<0) + sqrt(x*(x>=0))

(Note the locations of the parentheses for the sqrt expression.)

Darryl K. Nester                E-mail: mailto:nesterd@bluffton.edu
Assoc. Prof. of Mathematics        WWW: http://www.bluffton.edu/~nesterd
Bluffton College                 Phone: 419-358-3483
Bluffton, OH  45817-1704           Fax: 419-358-3232


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