Notice that
so the constraint is a set of two lines,
and only the first line passes through the first quadrant.
The distance between any point 
in the plane is 
, but we know that 
and 
share the same critical points, so we need only worry about minimizing 
. The Lagrangian for this problem is then
with partial derivatives (set equal to 0)
We have
which tells us that
so that 
is a critical point. The Hessian for the target function is
which is positive definite for all 
, so the critical point is the site of a minimum. The minimum distance itself (which we don't seem to care about for this problem, but we might as well state it) is 
.
Let d = the length of the trail, miles
Note that
distance = speed * time
or
time = distance / speed.
The time, t₁, to travel the trail at 3 miles per hour is
t₁ = d/3 hours
The time, t₂, to travel back at 5 miles per hour is
t₂ = d/5 hours
Because the total time is 3 hours, therefore
t₁ + t₂ = 3
d/3 + d/5 = 3
d(1/3 + 1/5) = 3
d(8/15) = 3
Multiply each side by 15.
8d = 3*15 =45
d = 45/8 = 5 5/8 miles or 5.625 miles
Total distance = 2*d = 11.25 miles or 11 1/4 miles.
t₁ = 5.625/3 = 1.875 hours or 1 hour, 52.5 minutes
t₂ = 5.625/5 = 1.125 hours or 1 hour , 7.5 minutes
Answers ;
Time to travel at 3 miles per hour = 1.875 hours (1 hour, 52.5 minutes)
Time to return at 5 miles per hour = 1.125 hours (1 hour, 7.5 minutes)
Total distance traveled = 2*d = 11.25 miles.
Answer:
Step-by-step explanation:
Since both triangles are similar, we know this because they have 2 angles in common, they both have the same third angle.
To find the third angle, we use the angle sum. The sum of angles in a triangle will always equal 180 degrees. We are given a right angle which is 90 degrees and another angle, which is 53 degrees. Knowing this:
90 + 53 + x = 180 (I have chosen to call the third angle x)
when rearranging this we get
180 - 90 - 53 = x
now we solve
x = 37 degrees
Hope this helps,
Cate
Answer:
0x2+9x-3x-27 6x-27
Step-by-step explanation:
The answer is 36,000 because 1 km=1,000 m. Since 1 liter is used every 12 km and you are finding out how many m you will go, you change the km to m and you will multiply it by 3.
12,000x3=36,000 m
