Find the equation of the curve that joins the following points. Hint: Use common differences.

a. The zeros of the function are 3,-1,-5. The y-intercept is 15. Find the function.

b. (1,1), (0,1), (2,-5), (-1,-5)

1 answer

a. x = 3
x-3 = 0

x = -1
x+1 = 0

x = -5
x+5 = 0

Y = (x-3)(x+1)(x+5) = 0
Multiply the 1st two parenthesis:
Y = (x^2-2x-3)(x+5) = 0
Eq: Y = x^3 + 3x^2 -13x - 15 = 0