Using the included equations, compare x-intercept(s), y-intercept(s), and intersecting point(s) of the linear and quadratic functions.

f(x)=(x+3)^2 and g(x) = 2x+6

Responses:

Both Linear and Quadratic share the x-intercept at (-3, 0). They have different y-intercepts; Linear y-intercept is 6 and Quadratic y-intercept is 9. They also share the point (-1, 4).

Both Linear and Quadratic share their x- and y-intercepts. Their x-intercept is -1 and their y-intercept is 4. They intersect at the point (-3, 0)

These graphs have no shared points.

1 answer

To analyze the functions and find their x-intercepts, y-intercepts, and any points of intersection, let's evaluate both functions given:

  1. Quadratic Function: \( f(x) = (x+3)^2 \)

    • Finding the x-intercept(s): Set \( f(x) = 0 \): \[ (x + 3)^2 = 0 \] Taking the square root, we get: \[ x + 3 = 0 \Rightarrow x = -3 \] So, the x-intercept of \( f(x) \) is at the point: (-3, 0).

    • Finding the y-intercept: Set \( x = 0 \): \[ f(0) = (0 + 3)^2 = 9 \] Thus, the y-intercept of \( f(x) \) is at the point: (0, 9).

  2. Linear Function: \( g(x) = 2x + 6 \)

    • Finding the x-intercept(s): Set \( g(x) = 0 \): \[ 2x + 6 = 0 \] Solving for \( x \): \[ 2x = -6 \Rightarrow x = -3 \] So, the x-intercept of \( g(x) \) is also at the point: (-3, 0).

    • Finding the y-intercept: Set \( x = 0 \): \[ g(0) = 2(0) + 6 = 6 \] Thus, the y-intercept of \( g(x) \) is at the point: (0, 6).

  3. Finding the intersection point(s): We set \( f(x) = g(x) \): \[ (x + 3)^2 = 2x + 6 \] Expanding and rearranging: \[ x^2 + 6x + 9 = 2x + 6 \] \[ x^2 + 4x + 3 = 0 \] Factoring gives: \[ (x + 1)(x + 3) = 0 \] This provides roots \( x = -1 \) and \( x = -3 \).

    • For x = -1: \[ f(-1) = (-1 + 3)^2 = 4 \quad \text{and} \quad g(-1) = 2(-1) + 6 = 4 \] So, they intersect at: (-1, 4).
  4. Summary of intercepts and intersection:

    • x-intercept: Both \( f(x) \) and \( g(x) \) have the same x-intercept at (-3, 0).
    • y-intercept: \( f(x) \) has a y-intercept at (0, 9) while \( g(x) \) has a y-intercept at (0, 6).
    • Intersection Point: They intersect at (-1, 4).

Therefore, the correct response based on this analysis is:

Both Linear and Quadratic share the x-intercept at (-3, 0). They have different y-intercepts; Linear y-intercept is 6 and Quadratic y-intercept is 9. They also share the point (-1, 4).