Example:
This suggests two solutions,
and
.
However, upon plugging these solutions back into the equation, you get
which checks out, but
does not because
is defined only for
(assuming you're looking for real solutions only). So, we call
an extraneous solution, and the complete solution set (over the real numbers) is
.
The expression for the number of segments drawn out of the n number of points in the circle is,
n² / 2 - n / 2
Substituting directly to the expression the number of points, n, which is equal to 8,
8² / 2 - 8 / 2 = 28
Thus, there are 28 segments that can be drawn from the points.
Answer:
a = 22
b = 31
c = 13
Step-by-step explanation:
The sum is the same in each row, column, and diagonal.
One of the diagonals is already complete. The sum is:
16 + 25 + 34 = 75
So the first row adds up to 75:
a + 37 + 16 = 75
a = 22
The second row adds up to 75:
19 + 25 + b = 75
b = 31
And the third row adds up to 75:
34 + c + 28 = 75
c = 13
We can check our answer by finding the sum of each column and the other diagonal.
22 + 19 + 34 = 75
37 + 25 + 13 = 75
16 + 31 + 28 = 75
22 + 25 + 28 = 75
Best to find the equation of the parabola first:
Its equation is y+12.5 = (x+1.5)^2, or y = -12.5 + (x+1.5)^2
Check the first possible x-intercept: let x = -2. Does y come out to 0?
y = -12.5 + (-0.5)^2 = -12.5 + 0.25. This is not equal to 0, so (-2,0) is not an x-intercept of this parabola. Continue checking each possible x-intercept until you find the right one (or ones).
