Questions: Solve the polynomial inequality and graph the solution set on a number line. Express the solution set in interval notation.
x^2-12x+36>0
Transcript text: Solve the polynomial inequality and graph the solution set on a number line. Express the solution set in interval notation.
\[ x^{2}-12 x+36>0 \]
Solution
Solution Steps
To solve the polynomial inequality \(x^2 - 12x + 36 > 0\), we first find the roots of the corresponding equation \(x^2 - 12x + 36 = 0\). This will help us determine the intervals to test for the inequality. After finding the roots, we test intervals around these roots to see where the inequality holds true. Finally, we express the solution set in interval notation.
Step 1: Identify the Polynomial
The given polynomial inequality is:
\[
x^2 - 12x + 36 > 0
\]
Step 2: Factor the Polynomial
First, we need to factor the quadratic expression \(x^2 - 12x + 36\). Notice that this is a perfect square trinomial:
\[
x^2 - 12x + 36 = (x - 6)^2
\]
Step 3: Analyze the Inequality
We need to solve the inequality:
\[
(x - 6)^2 > 0
\]
The expression \((x - 6)^2\) is a square of a binomial, which is always non-negative. It equals zero when \(x = 6\). Therefore, \((x - 6)^2 > 0\) for all \(x\) except \(x = 6\).
Step 4: Determine the Solution Set
Since \((x - 6)^2 > 0\) for all \(x \neq 6\), the solution set is all real numbers except \(x = 6\).
Step 5: Express the Solution in Interval Notation
The solution set in interval notation is:
\[
(-\infty, 6) \cup (6, \infty)
\]
Step 6: Graph the Solution Set on a Number Line
To graph the solution set on a number line:
Draw a number line.
Place an open circle at \(x = 6\) to indicate that this point is not included in the solution set.
Shade the regions to the left of \(x = 6\) and to the right of \(x = 6\) to indicate that all other real numbers are included in the solution set.