Javier L. answered 03/04/21
Learn Python and Math from a Silicon Valley Computer Engineer
Short answer: y = x2 - 7x - 10
Long Answer:
Use your roots and set them up as binomials.
Polynomials have a property where they will equate to zero when the variable of interest is equal to the root.
First order binomials (exponent of 1) can be expressed as:
(x - a)
where a = root
To find a root of a polynomial, set it equal to zero:
x - a = 0
x = a
A quadratic equation is the product of two first order binomials:
y = (x-a)(x-b)
So let’s test this property defined above:
Set y = 0,
0 = (x-a)(x-b)
if we divide by (x-b):
0 = (x-a)
x = a
this is our first root
if we divide by (x-a):
0 = (x-b)
x = b
this is our second root
back to the point, we can plug in our two roots:
y = (x-(-3))(x-10)
y = (x+3)(x-10)
we find the product through FOIL:
(x•x) + (-10 • x) + (3 • x) + (3 • -10)
y = x^2 - 10x + 3x - 10
y = x^2 - 7x - 10