In the following functions, evaluate c so that f(x) will be the probability density function:
a. f(x) =c/(x^4), x>1
b. f(x;theta)= c(ln theta)theta^-1, x>0, theta>1
c. f(x;theta)= c/3(theta +1)x^theta, 00
d. f(x;theta)=2c(1+2thetax-3thetax^2), 0
e. f(x)=ce^-(x/theta), theta>0
f. f(x) = c/(1+x^2), -infinity