The equation of a sphere is:
(x – h)^2 + (y – k)^2 + (z – l)^2 = r^2
where h, k and l are the coordinates of the center of the
sphere
Using the midpoint formula, the coordinate of the center
is:
h = (-4 + 6) / 2 = 1
k = (7 + -5) / 2 = 1
l = (6 + 7) / 2 = 6.5
so the equation becomes:
(x – 1)^2 + (y – 1)^2 + (z - 6.5)^2 = r^2
we plug in any point, in this case point P to solve for r:
(-4 -1)^2 + (7 – 1)^2 + (6 - 6.5)^2 = r^2
r^2 = 61.25
So the full equation is:
<span>(x – 1)^2 + (y – 1)^2 + (z - 6.5)^2 = 61.25</span>
Answer:
7.5
Step-by-step explanation:
The relation between time, speed, and distance is ...
time = distance/speed
If distance is "1 round trip", then the time going is ...
going = 0.5/(10 mi/h) . . . . for 1/2 round trip
and the time coming is ...
coming = 0.5/(6 mi/h)
Then the average speed for the full round trip is ...
speed = distance/time
average speed = 1/(going + coming) = 1/(0.5/10 +0.5/6) mi/h
= 1/((3+5)/60) mi/h
= 60/8 mi/h = 7.5 mi/h
Jack's average speed for the round trip was 7.5 mph.
Answer:
D is the largest angle
Step-by-step explanation:
The angle opposite the largest side is the largest and the angle opposite the smallest side is the smallest.
Since 12 is the largest side, angle D is the largest
8 is the smallest side, F is the smallest angle