f(x)=6x^3+19x^2+8x-5

Question

find all the zeros of the given function

Answer 1

If a cubic always try dividing by (x-1) and by (x+1) first to see if 1 or -1 is a root.
In this case:
x = -1 , 1/3 , -2 1/2
if all else fails:
http://www.solvemymath.com/online_math_calculator/algebra_combinatorics/polynomial_calculator/polynomial_roots.php