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**acasas4** The pdf of a random variable X is given by f(x)=c(1-x^2) for x element of (-1,1) (the element of symbol that looks like a curved E). For which values of c is this function actually a pdf? (c being a constant)

I know that in order for something to be a pdf it must meet the requirements that

*p(x)*>or= 0 for all x

and

the probabilities must sum to 1.

Where I am confused is by the element of (-1,1) I am not sure how to solve this with an interval.

Thanks to anyone who can help.

(I attached the equation in a word doc just in case my notation above is confusing)