Find the Domain of (x+10)²+2: Analyzing Positive and Negative Inputs

Question

Find the positive and negative domains of the function below:

y=(x+10)2+2 y=\left(x+10\right)^2+2

Step-by-Step Solution

The function given is y=(x+10)2+2 y = (x+10)^2 + 2 . This is a quadratic function in vertex form.

The vertex form of a quadratic function is y=a(xh)2+k y = a(x-h)^2 + k , where the vertex is (h,k)(h, k). For our function, h=10 h = -10 and k=2 k = 2 , so the vertex is (10,2)(-10, 2).

In this case, since the coefficient of (x+10)2(x+10)^2 is positive (implicitly 1), the parabola opens upwards. This means the function has a minimum point at the vertex, and y y will only increase from that point.

Given that the vertex point has a y y -value of 2, which is positive, the entire domain yields values of y y that are greater than 2. Therefore, y y will never be negative.

Now, let's determine the domains:

  • For the negative domain, we seek values of x x where the function y y is negative. Since the minimum y y -value is 2, no such x x satisfies y<0 y \lt 0 . Hence, there is no negative domain.
  • Similarly, all values of x x yield a positive range of y y , as y2 y \geq 2 for all x x . Thus, for the positive domain, it is all x x , as every y y value is positive or zero.

Consequently, the specified positive domain is all x x , and the negative domain is none.

Thus, the correct answer is:

x<0: x < 0 : None

x>0: x > 0 : All x x

Answer

x < 0 : None

x > 0 : All x x