The function below has at least one rational root. Find the y-intercept and use the rational roots theorem to find all rational roots. Fill in the sign table and sketch a graph below. Your graph must accurately cross all known intercepts.
f(x)= 2x^3 +4x^2 -8x -16
Identify the y-intercept of the function.
To find the y-intercept, we need to evaluate the function at x = 0:
f(0) = 2(0)^3 + 4(0)^2 - 8(0) - 16
f(0) = -16
Therefore, the y-intercept is -16.