Determine the Intersection Points of y = (x - 9)(x + 7) with the X-Axis

Question

Determine the points of intersection of the function

y=(x9)(x+7) y=(x-9)(x+7)

With the X

Video Solution

Solution Steps

00:00 Find the intersection points with the X-axis
00:03 At the intersection with the X-axis, the Y value must = 0
00:07 Substitute Y = 0 and solve for X values
00:14 Find what zeroes each factor in the product
00:21 This is one solution
00:29 This is the second solution
00:38 And this is the solution to the question

Step-by-Step Solution

To solve this problem, we'll determine where the function intersects the x-axis by following these steps:

  • Step 1: Set the function equal to zero to find the roots.
  • Step 2: Solve each factor of the equation independently for x x .
  • Step 3: Confirm the intersection points as the solutions.

Now, let's work through each step:
Step 1: Given the function y=(x9)(x+7) y = (x-9)(x+7) , set y=0 y = 0 to find the x-intercepts:
(x9)(x+7)=0 (x-9)(x+7) = 0 .

Step 2: Solve the equation:
The expression (x9)(x+7)=0(x-9)(x+7) = 0 implies that either x9=0x-9 = 0 or x+7=0x+7 = 0.

Solving each equation:
For x9=0x-9 = 0, solve for xx:
x=9x = 9.
For x+7=0x+7 = 0, solve for xx:
x=7x = -7.

Step 3: Therefore, the points of intersection are where y=0y = 0, which occur at:

The solutions are x=9x = 9 and x=7x = -7.

The coordinates of these intersection points, given y=0y = 0 at each root, are (7,0)(-7, 0) and (9,0)(9, 0).

Therefore, the solution to the problem is (7,0),(9,0)(-7, 0), (9, 0).

Answer

(7,0),(9,0) (-7,0),(9,0)