Find the Domain of (x-2 1/9)² + 5/6: Positive and Negative Regions

Question

Find the positive and negative domains of the function below:

y=(x219)2+56 y=\left(x-2\frac{1}{9}\right)^2+\frac{5}{6}

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Recognize that the given quadratic function is in vertex form y=(xh)2+k y = (x - h)^2 + k , where h=219 h = 2\frac{1}{9} and k=56 k = \frac{5}{6} .
  • Step 2: Identify that the squared term (x219)2 (x - 2\frac{1}{9})^2 is always non-negative for any real x x .
  • Step 3: Note that the smallest value that the squared term can obtain is 0, which happens when x=219 x = 2\frac{1}{9} . Therefore, the smallest value of the whole function y y is 56 \frac{5}{6} , which is positive. Thus, y y is never negative.
  • Step 4: Conclude by identifying the domains: y<0 y < 0 has no solutions and y>0 y > 0 for all x x .

After considering the nature of the quadratic function:

Since y y cannot be negative, the negative domain is none, which means there are no values where y<0 y < 0 .

On the other hand, for all x x , y y is positive because the minimum value y y can take is the constant term 56\frac{5}{6}, which is positive.

Thus, the solution is:

x<0: x < 0 : none

x>0: x > 0 : for all x x

Answer

x < 0 : none

x > 0 : for all x x