Question

Write a cubic function whose graph goes through the points: (-5, 0) (1, 0) (2, -2) (4, 0)

Answer 1

Answer:

f(x) = $\frac{1}{7}(x+5)(x-1)(x-4)$

Step-by-step explanation:

Let the equation of the give cubic function is,

f(x) = p(x - a)(x - b)(x - c)

Here, a, b, c and d are the x-intercepts of the given graph.

Since, x-intercepts given in the graph are x = -5, 1 and 4,

Equation of the curve will be,

f(x) = p(x + 5)(x - 1)(x - 4)

Since, the graph of this function passes through (2, -2) also

-2 = p(2 + 5)(2 - 1)(2 - 4)

-2 = -p(14)

p = $\frac{2}{14}$

p = $\frac{1}{7}$

Therefore, equation will be,

f(x) = $\frac{1}{7}(x+5)(x-1)(x-4)$