Given three points of a quadratic function, find the equation that defines the function: (-2, 20)(0, -2)(1, -4)

Step-by-step explanation:

Let the quadratic function be

The given points must satisfy this function;

Substitute .

Substitute (0,-2)

Substitute (1,-4);

Put equation (2) into equation (1)

Put equation (2) into equation (3)

Add equation (4) and (5)

Divide both sides by 3

Put a=3 in  equation 5.

The quadratic function is;

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have