Answer:
4 meters
Step-by-step explanation:
Let the height at which the top of the ladder is be represented by h. The sketch of the question forms a right angled triangle. So that applying the Pythagoras rule,
= +
= +
25 = + 9
= 25 - 9
= 16
⇒ h =
= 4
Therefore, the height at which the top of ladder is placed is 4 meters.
First, we have to convert our function (of x) into a function of y (we revolve the curve around the y-axis). So:
And the derivative of x:
Now, we can calculate the area of the surface:
We could calculate this integral (not very hard, but long), or use
(1),
(2) and
(3) to get:
Calculate indefinite integral:
And the area:
Answer D.
Answer:
equal
Step-by-step explanation:
Most quadratic equations have <em>equal</em> roots.
Answer:
(20 + n)¢
Step-by-step explanation:
With Company X, it costs 35¢ to connect and then 5¢ for each minute.
So, for n minutes of calling the company X charges, C(x) = (35 + 5n)¢
Again, With Company Y, it costs 15¢ to connect and then 4¢ for each minute.
So, for n minutes of calling the company Y charges, C(y) = (15 + 4n)¢.
Therefore, the company Y charges for n minutes of calling less than company X is [(35 + 5n) - (15 + 4n)]¢ = (20 + n)¢ (Answer)
Answer:
Bernie left home riding his bike at a rate of 15 mph.
Charlie left one hour later biking at a rate of 20 mph.
Bernie distance = 15*t (time is represented by t)
Charlie distance = 20*(t-1) (he left after 1 hour)
15t = 20t - 20
-5t = -20
t = 4
4*15 = 60
when t = 3 hours
3*20 = 60