The following is a function that is positive in domain:
3 < x
Choose the equation that describes it given that the absolute value of the slope is 2.
To address this problem, we follow these steps:
- Step 1: A linear function in slope-intercept form is y=mx+c. Given slope ∣m∣=2, possible equations are y=2x+c and y=−2x+c.
- Step 2: Consider positivity for x>3 condition.
- For y=2x+c : We need y=2x+c>0. Solving yields 2x>−c, meaning the function is positive when x>2−c.
- For y=−2x+c: Similarly, −2x+c>0 provides c>2x or x<2c, implying negativity above x=2c.
- Step 3: Examine behavior at x=3:
- For y=2x+c, it should be 2(3)+c>0; simplifying: 6+c>0→c>−6.
- For y=−2x+c, since positive domain minimum is x>3, it’s negative x>2c.
- Step 4: Confirms the correct function must work for any c>−6, resultant choice: y=2x−6. It remains positive as x increases past 3.
Thus, the correct equation satisfies all parameters: y=2x−6.