The rate of separation = 25 + 15 = 40 mph
speed = distance / time
40 = 30 / t
t = 30/40 hour = 45 minutes
Its C.
Answer:
The answer is (C)
The equation of the circle is (x + 4)² + (y - 6)² = 81
Step-by-step explanation:
* To find the equation of the circle you need to know
the center of the circle and the length of its radius
* The rule of the equation of the circle is:
(x - h)² + (y - k)² = r²
Where x and y is a general point on the circle,
h and k are the coordinates of the center of the circle
and r is the radius of the circle
∵ The center of the circle is (-4 , 6)
∵ The radius of the circle is 9
∴ (x - -4)² + (y - 6)² = 9²
∴ ( x + 4)² + (y - 6)² = 81
∴ The answer is (C)
Answer:
Is this algebra, or does "x" represent multiplying?
Step-by-step explanation:
Answer:
the averege is 2.34
duh
Step-by-step explanation:
9514 1404 393
Answer:
x = 10·cos(θ) -4·cot(θ)
Step-by-step explanation:
Apparently, we are to assume that the horizontal lines are parallel to each other.
The relevant trig relations are ...
Sin = Opposite/Hypotenuse
Cos = Adjacent/Hypotenuse
If the junction point in the middle of AB is labeled X, then we have ...
sin(θ) = 4/BX ⇒ BX = 4/sin(θ)
cos(θ) = x/XA ⇒ XA = x/cos(θ)
Then ...
BX +XA = AB = 10
Substituting for BX and XA using the above relations, we get
4/sin(θ) +x/cos(θ) = 10
Solving for x gives ...
x = (10 -4/sin(θ))·cos(θ)
x = 10·cos(θ) -4·cot(θ) . . . . . simplify
_____
We used the identity ...
cot(θ) = cos(θ)/sin(θ)
