A circle is graphed in the coordinate plane with the equation x2 + y2 = 81. At what points does the graph intersect the y-axis?
1 answer:
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The plus-minus sign represents that there are two possible outcomes.
In this case, we have
. When we branch out the possibilities we got 2 values: 
and 
Those are the roots of this equation. When they ask their product, they want you to multiply both numbers.
When we multiply them:
When we FOIL the we get:
Simplify:
So the product of the two roots of this equation is 6.
In this case, we have
Those are the roots of this equation. When they ask their product, they want you to multiply both numbers.
When we multiply them:
When we FOIL the we get:
Simplify:
So the product of the two roots of this equation is 6.
Given:
Consider the below figure attached with this question.
To find:
The perimeter of the polygon UVWXYZ.
Solution:
All sides and vertical and horizontal. So, we can easily find the side lengths of the given polygon by counting the boxes between two points.
From the figure it is clear that,
UV = 9 units
VW = 2 units
WX = 3 units
XY = 3 units
YZ = 6 units
ZU = 5 units
Now, perimeter is the sum of all the sides.
Therefore, the perimeter of UVWXYZ is 28 units.
