Find Domains: Analyzing y=-(x-3 1/12)² - 1/7 Function

Question

Find the positive and negative domains of the function below:

y=(x3112)217 y=-\left(x-3\frac{1}{12}\right)^2-\frac{1}{7}

Step-by-Step Solution

The given quadratic function is y=(x3112)217 y = -\left(x - 3\frac{1}{12}\right)^2 - \frac{1}{7} . We start by understanding that the shape of this parabola will open downwards due to the negative sign in front of the square term. To find the roots or x-intercepts, set y=0 y = 0 .

Rewriting the expression for clarity, we have:

0=(x3712)217 0 = -\left(x - \frac{37}{12}\right)^2 - \frac{1}{7}

We can solve this by isolating the squared term:

(x3712)2=17 \left(x - \frac{37}{12}\right)^2 = -\frac{1}{7}

Since a squared term cannot be negative, it illustrates that there are no real roots. This means the parabola does not cross the x-axis and remains entirely below it, due to the downward opening.

Therefore, the function is negative (y<0 y < 0 ) for all x-values. The positive domain is non-existent.

The solution tells us:

  • x<0: x < 0 : all x x
  • x>0: x > 0 : none

In terms of given choices: the correct choice is 3.

The solution to the problem is that the positive and negative domains are:

x<0: x < 0 : all x x

x>0: x > 0 : none

Answer

x < 0 : all x x

x > 0 : none