How to determine the probability density function

Determining if it is a probability density

Simply calculate it, and the answer is shown

How to determine the probability density function

f(x) is the density of a random variable if and only if

1) f(x)>=0; 2) f(x) integrates from -∞ to +∞ as 1.

How do I see if it is a density function ah

The density function requires that the value of the function at each point is not less than 0 (the probability cannot be negative),

and that the value of the definite integral of the interval is equal to 1 (the probability sums up to 1).

Only then can it be called P(X=x)=f(x)