Find the Positive Area: Solving y=(x+5)² Above the X-axis

Question

Find the positive area of the function
y=(x+5)2 y=(x+5)^2

Video Solution

Solution Steps

00:00 Find the positive domain of the function
00:03 Use shortened multiplication formulas and expand the parentheses
00:09 Look at the coefficient of X squared, positive
00:13 When the coefficient is positive, the function smiles
00:19 Now we want to find the intersection points with the X-axis
00:25 At the intersection point with X-axis, Y=0, we'll substitute and solve
00:30 Take out the root to get rid of the exponent
00:41 Isolate X
00:44 This is the X value at the intersection point with X-axis
00:48 Draw the function according to intersection points and function type
00:55 The function is positive while it's above the X-axis
01:06 And this is the solution to the question

Step-by-Step Solution

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

  • Step 1: Identify where the quadratic expression (x+5)2(x+5)^2 equals zero, as this determines when y=0y=0.
  • Step 2: Solve the equation (x+5)2=0(x+5)^2 = 0 to find values of xx.
  • Step 3: Determine the values of xx where (x+5)2>0(x+5)^2 > 0.

Now, let's work through each step:

Step 1: We need to analyze the expression (x+5)2(x+5)^2.

Step 2: Solve (x+5)2=0(x+5)^2 = 0.
The equation simplifies to:

(x+5)=0(x+5) = 0
Solve for xx:
x=5x = -5

Step 3: Determine xx values where (x+5)2(x+5)^2 is positive.
The expression (x+5)2(x+5)^2 is positive for any x5x \neq -5, because the square of a non-zero real number is always positive.

Therefore, the quadratic (x+5)2(x+5)^2 is positive for x5x \neq -5, meaning the positive area applies for all xx except x=5x = -5.

The correct choice is: For each x5x \neq -5.

Therefore, the solution to the problem is For each x5x \neq 5.

Answer

For each X x5 x\ne5