1. ## CDF

Deteremine if the function F is a CDF and if so, find the corresponding PDF

F(x)= 0 if x<= 1
((x-1)^2)/(8) if 1<=x<3
1 if 3<=x

i just don't understand how to determine if its a CDF.

2. Originally Posted by durham2
Deteremine if the function F is a CDF and if so, find the corresponding PDF

F(x)= 0 if x<= 1
((x-1)^2)/(8) if 1<=x<3
1 if 3<=x

i just don't understand how to determine if its a CDF.
Is $F(x) \geq 0$ for all values of x? Does F(x) = 1 for $x \geq 3$?

Therefore ....?

3. Originally Posted by mr fantastic
Is $F(x) \geq 0$ for all values of x? Does F(x) = 1 for $x \geq 3$?

Therefore ....?
do you just take the integration of it to find the PDF??

4. Originally Posted by durham2
do you just take the integration of it to find the PDF??
No. I'm sure your notes will say to take the derivative: $f(x) = \frac{dF}{dx}$.