9514 1404 393
(13.06, 16.41)
Step-by-step explanation:
Any point not on a perpendicular bisector of the line between towns will be closer to one town than the other. So, the intersection of perpendicular bisectors will be the equidistant from all towns. That point is the circumcenter of the circle circumscribing the triangle with the towns as its vertices. This can be found as the intersection of two perpendicular bisectors of the segments between the towns.
The midpoint of AB is ...
(A +B)/2 = ((15, 3) +(25, 10))/2 = (40, 13)/2 = (20, 6.5)
The midpoint of AC is ...
(A +C)/2 = ((15, 3) +(0, 20))/2 = (15, 23)/2 = (7.5, 11.5)
__
The differences between points are ...
B -A = (25, 10) -(15, 3) = (10, 7)
C -A = (0, 20) -(15, 3) = (-15, 17)
Then the perpendicular bisector equations can be written as ...
bisector of AB ⇒ 10(x -20) +7(y -6.5) = 0
10x +7x -245.5 = 0
bisector of AC ⇒ -15(x -7.5) +17(y -11.5) = 0
-15x +17y -83 = 0
These have coefficients that aren't particularly nice, so a method similar to Cramer's Rule is suitable for solving this pair of equations. Using the "cross multiplication method", we have ...
x = (7(-83) -17(-245.5))/(10(17) -(-15)(7)) = 3592.5/275 = 13 7/110 ≈ 13.06
y = (-245.5(-15) -(-83)(10))/275 = 4512.5/275 = 16 9/22 ≈ 16.41
The point as far as possible from each town within the boundary of the island has coordinates (13.06, 16.41).
_____
Further detail regarding the solution
Here, we have written the equation for the perpendicular bisector this way. The difference in coordinates between points R and S can be called ...
R -S = (∆x, ∆y)
The midpoint of segment RS can be called ...
(R +S)/2 = (h, k)
Then the line that is a perpendicular bisector of RS can be written as ...
∆x(x -h) +∆y(y -k) = 0
This is the form that is used above.
__
The "cross multiplication method" for solving a pair of general-form linear equations ...
ax +by +c = 0
dx +ey +g = 0
will give the solution as ...
1/(ae -db) = x/(bg -ec) = y/(cd -ga)
If you write the coefficients in two rows of four, the pattern of products and differences is easy to see.
9514 1404 393
(13.06, 16.41)
Step-by-step explanation:
Any point not on a perpendicular bisector of the line between towns will be closer to one town than the other. So, the intersection of perpendicular bisectors will be the equidistant from all towns. That point is the circumcenter of the circle circumscribing the triangle with the towns as its vertices. This can be found as the intersection of two perpendicular bisectors of the segments between the towns.
The midpoint of AB is ...
(A +B)/2 = ((15, 3) +(25, 10))/2 = (40, 13)/2 = (20, 6.5)
The midpoint of AC is ...
(A +C)/2 = ((15, 3) +(0, 20))/2 = (15, 23)/2 = (7.5, 11.5)
__
The differences between points are ...
B -A = (25, 10) -(15, 3) = (10, 7)
C -A = (0, 20) -(15, 3) = (-15, 17)
Then the perpendicular bisector equations can be written as ...
bisector of AB ⇒ 10(x -20) +7(y -6.5) = 0
10x +7x -245.5 = 0
bisector of AC ⇒ -15(x -7.5) +17(y -11.5) = 0
-15x +17y -83 = 0
These have coefficients that aren't particularly nice, so a method similar to Cramer's Rule is suitable for solving this pair of equations. Using the "cross multiplication method", we have ...
x = (7(-83) -17(-245.5))/(10(17) -(-15)(7)) = 3592.5/275 = 13 7/110 ≈ 13.06
y = (-245.5(-15) -(-83)(10))/275 = 4512.5/275 = 16 9/22 ≈ 16.41
The point as far as possible from each town within the boundary of the island has coordinates (13.06, 16.41).
_____
Further detail regarding the solution
Here, we have written the equation for the perpendicular bisector this way. The difference in coordinates between points R and S can be called ...
R -S = (∆x, ∆y)
The midpoint of segment RS can be called ...
(R +S)/2 = (h, k)
Then the line that is a perpendicular bisector of RS can be written as ...
∆x(x -h) +∆y(y -k) = 0
This is the form that is used above.
__
The "cross multiplication method" for solving a pair of general-form linear equations ...
ax +by +c = 0
dx +ey +g = 0
will give the solution as ...
1/(ae -db) = x/(bg -ec) = y/(cd -ga)
If you write the coefficients in two rows of four, the pattern of products and differences is easy to see.
Part A:
Answer
One of Roosevelt's purposes was to inform the American people of Japan's attack on the US and other places in the Pacific.
The other possible answer is the one that mentions Japan being an ally of the Nazis, however the word "Nazi" is never mentioned on the speech.
Part B:
Answer
He uses repetition, employing the word ¨attack¨ over and over, to inspire Americans to join the armed forces and aggressively take on the enemy.
This is definitely the rhetoric that applies to advance his purpose from part A. The other options wouldn't apply.
Part A:
Answer
One of Roosevelt's purposes was to inform the American people of Japan's attack on the US and other places in the Pacific.
The other possible answer is the one that mentions Japan being an ally of the Nazis, however the word "Nazi" is never mentioned on the speech.
Part B:
Answer
He uses repetition, employing the word ¨attack¨ over and over, to inspire Americans to join the armed forces and aggressively take on the enemy.
This is definitely the rhetoric that applies to advance his purpose from part A. The other options wouldn't apply.
Part A
The correct answer is "to inform the American people of Japan's attack on the US and other places in the Pacific ."
Part B
The correct answer is "He uses repetition, employing the word "attack" over and over, to inspire Americans to join the armed forces and aggressively take on the enemy."
12a,
13d,
14c,
15d,
16a,
17d,
18c,
19c,
20d,
21d,
22c,
23b
,24c
26,d
12a,
13d,
14c,
15d,
16a,
17d,
18c,
19c,
20d,
21d,
22c,
23b
,24c
26,d
12a,
13d,
14c,
15d,
16a,
17d,
18c,
19c,
20d,
21d,
22c,
23b
,24c
26,d
It will provide an instant answer!