y =
To construct a cubic function in intercept form with integer x-intercepts and a constant factor a of either 1 or -1, we consider the properties of intercepts and the general form of cubic functions. The intercept form of a cubic function is given by y=a(x−r1)(x−r2)(x−r3), where r1, r2 and r3 are the x-intercepts.
To maintain simplicity and meet the specified conditions, we choose a=1 and opt for three distinct integer roots (r1, r2 and r3).
The function will be cubic. The x-intercepts are -4, -1, and 2
The constant factor is -1 because the graph falls on the right. So,
y = -(x + 4)(x + 1)(x - 2)
y=-x^3-2x^2+5x+6