Let f(x)=x+3x2−4. Which one of the following statements about the value of x→1limf(x) and f(1) is correct?
a) x→1limf(x) exists but is not equal to f(1).
b) Neither x→1limf(x) nor f(1) exists.
c) Both x→1limf(x) and f(1) exist and are equal.
d) x→1limf(x) does not exist but f(1) exists.