To solve this problem you must apply the proccedure shown below:
1- You have that the laddder makes an angle of 
with the ground and the top of the ladder reaches 
.
2- Therefore, you have:
Where:
3-You must substitute values and solve for the lenght, as following:
Therefore, the answer is: 
Step-by-step explanation:
(7x^4-4y^8)^2
The answer to your problem is 1/2!
A. The term "units" refers to the measurements in the original question or problem. When looking at the question, the units we are measuring are dollars/feet.
B. In this case, the f'(x) means we are looking for the cost (in dollars) to drill the next foot down.
C. Since the cost increases the more feet we drill down, the sign of f'(x) is positive.
