Answer:
r=13
Step-by-step explanation:
Step-by-step explanation:
you drew already the right things, you have everything.
so, what is the problem ?
the most common form of line equation is
y = ax + b
a is the slope of the line. it is expressed as the ratio
y coordinate change / x coordinate change
when going from one point to the other.
b is the y-intercept (the y value when x = 0).
once we have the slope, we get b by using the coordinates of one of the given points as x and y in the equation and solve for b.
so, for the 2 marked points you showed correctly the differences :
x changes by +8 (from -4 to 4).
y changes by -2 (from 3 to 1).
so the slope is -2/+8 = -1/4
the y-intercept we also see directly in the chart : +2.
You don't have the graph icon here, so we'll have to graph this parabola without it.
Your parabola is y = -x^2 + 3., which resembles y = a(x-h)^2 + k. We can tell immediately that this parabola opens down and that the vertex is (0,3).
Plot (0,3). Besides being the vertex, this point is also the max. of the function.
Now calculate four more points. Choose four arbitrary x-values, such as {-2, 1, 4, 5} and find the y value for each one. Plot the resulting four points. Draw a smooth curve thru them, remembering (again) that the vertex is at (0,3) and that the parabola opens down.
