the point with coordinates (2,-5) lies on the circumference. The center of this circumference has the coordinates (2,1). What is
the radius of this circle?
1 answer:
Answer: The radius is
r
=
3
.
Explanation:
If the point
(
−
3
,
2
)
belongs to the circle
(
x
+
3
)
2
+
(
y
+
1
)
2
−
r
2
=
0
then its coordinates must verify that equation. That is, if we substitute in the equation of the circle
x
by
−
3
and
y
by
2
we must obtain a true equality. Then, it is enough to clear
r
of that equation:
(
−
3
+
3
)
2
+
(
2
+
1
)
2
−
r
2
=
0
⇒
9
−
r
2
=
0
,
then:
r
=
√
9
=
3
.
(Remember
r
is a distance, then it's always a positive number).
Step-by-step explanation:
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In math remaining means left over.
Hope that helped:)
About 379.1666666666666
The 6 is repeating. Or about 379 if your rounding.
2x+5y=21, x+y=3
y=3-x
2x+5y=21
2x+5(3-x) =21
2x+15-5x=21
2x-5x+15=21
-3x+15=21
-3x=21-15
-x=6/3
-x=2
x=-2
I think you have to use the distance formula
Answer:
Step-by-step explanation:
