Solve the Quadratic Equation: Find Intersection Points of y=(x-2)(x+4)

Question

Determine the points of intersection of the function

y=(x2)(x+4) y=(x-2)(x+4)

With the X

Video Solution

Solution Steps

00:00 Find the intersection points with the X-axis
00:03 At the intersection point with the X-axis, the Y value must = 0
00:07 Substitute Y = 0 and solve for X values
00:13 Find what makes each factor in the product zero
00:19 This is one solution
00:28 This is the second solution
00:36 And this is the solution to the question

Step-by-Step Solution

To solve for the points of intersection of the function y=(x2)(x+4) y = (x-2)(x+4) with the x-axis, we proceed as follows:

  • Set the function equal to zero to find the x-intercepts: (x2)(x+4)=0 (x-2)(x+4) = 0 .
  • Apply the zero-product property, which tells us that if a product of factors equals zero, then at least one of the factors must be zero. Thus, we solve the equations:
  • x2=0 x-2 = 0 or x+4=0 x+4 = 0 .

Solving these equations, we find:

x2=0 x-2 = 0 gives x=2 x = 2 .

x+4=0 x+4 = 0 gives x=4 x = -4 .

Therefore, the points of intersection with the x-axis are the points where y=0 y=0 . Substituting these x-values into y=(x2)(x+4) y = (x-2)(x+4) , we confirm that the corresponding y-values are zero:

  • For x=2 x = 2 , the point is (2,0) (2,0) .
  • For x=4 x = -4 , the point is (4,0) (-4,0) .

Thus, the points of intersection are (4,0) (-4,0) and (2,0) (2,0) .

Answer

(4,0),(2,0) (-4,0),(2,0)