Question

Find rational roots of the polynomial f(x) = 2x³ +x² -7x -6.

Answer 1

We have

f(x) = 2x³ +x² -7x -6

Clearly, f(x) is a cubic polynomial with integer coefficient. If b/c is a rational roots in lowest terms, then the value of b are limited to the factors of 6 which +-1, +-2, +-3, +-6 and values of c are limited to the factors of 2 which are +-1, +-2. 

Hence, the possible rational roots of f(x) are