Final answer:
To solve the inequality 2x^3 > -18x^2, we factor the expression and use a number line to determine the sign in each interval. The solution is x ∈ (-∞, -9) ∪ (0, ∞).
Step-by-step explanation:
To solve the inequality 2x^3 > -18x^2, we need to find the values of x that satisfy the inequality. Here are the steps:
First, rewrite the inequality as 2x^3 + 18x^2 > 0.
Next, factor out the common term x^2 from both terms: x^2(2x + 18) > 0.
Set each factor equal to zero and solve for x to find the critical points: x^2 = 0 and 2x + 18 = 0. The solution for x^2 = 0 is x = 0, and the solution for 2x + 18 = 0 is x = -9.
Create a number line with these critical points and test intervals to determine the sign of the expression. The intervals are (-∞, -9), (-9, 0), and (0, ∞).
Choose a test point from each interval and substitute it into the inequality to determine the sign in each interval. For example, if we choose x = -10, then 2(-10)^3 + 18(-10)^2 = -1820, which is negative. We can do the same for other test points.
Based on the signs, we can conclude that the solution to the inequality is x ∈ (-∞, -9) ∪ (0, ∞) in interval notation.