Use the table to answer the question.

x f(x)=x^3+1 g(x)=x+1

−2 −7 −1

−1 0 0
0 1 1
1 2 2
2 9 3
Compare the functions f(x)=x3+1 and g(x)=x+1 . Which of the following statements is true about the intercepts of the functions?

Responses

The graphs intersect at (1,2).

Both functions have a y-intercept of (−1,0) and an x-intercept of (0,1)
both functions have a x-intercept of(-1,0) and a y-intercept of (0,1)
the x- and y intercepts are different for each function.

1 answer

To determine the correct statements about the intercepts of the functions \( f(x) = x^3 + 1 \) and \( g(x) = x + 1 \), let's first calculate the intercepts for both functions.

1. Y-Intercepts

  • For \( f(x) = x^3 + 1 \):

    • \( f(0) = 0^3 + 1 = 1 \)
    • So, the y-intercept is \( (0, 1) \).
  • For \( g(x) = x + 1 \):

    • \( g(0) = 0 + 1 = 1 \)
    • So, the y-intercept is also \( (0, 1) \).

2. X-Intercepts

  • For \( f(x) = x^3 + 1 \):

    • Set \( f(x) = 0 \): \[ x^3 + 1 = 0 \implies x^3 = -1 \implies x = -1 \]
    • So, the x-intercept is \( (-1, 0) \).
  • For \( g(x) = x + 1 \):

    • Set \( g(x) = 0 \): \[ x + 1 = 0 \implies x = -1 \]
    • So, the x-intercept is also \( (-1, 0) \).

Summary of Intercepts

  • Both functions have a y-intercept of \( (0, 1) \).
  • Both functions have an x-intercept of \( (-1, 0) \).

Analyzing the Given Statements

  1. The graphs intersect at (1,2).

    • This is false; at \( x = 1 \), \( f(1) = 2 \) and \( g(1) = 2 \), so they do intersect at that point, but it's not about the intercepts.
  2. Both functions have a y-intercept of (−1,0) and an x-intercept of (0,1).

    • This is false; they both have a y-intercept of \( (0, 1) \) and an x-intercept of \( (-1, 0) \), not the other way around.
  3. Both functions have a x-intercept of(-1,0) and a y-intercept of (0,1).

    • This is true; both functions have an x-intercept of \( (-1, 0) \) and a y-intercept of \( (0, 1) \).
  4. The x- and y-intercepts are different for each function.

    • This is false; the x- and y-intercepts are the same for both functions.

Conclusion

The correct statement is: Both functions have an x-intercept of (-1,0) and a y-intercept of (0,1).