Answer:
The rate of change is 
ft^(2)/min
Step-by-step explanation:
The area of a circle is given by the following equation:
To solve this question, we have to realize the implicit differentiation in function of t. We have two variables, A and r. So
We have that:
.
We want to find 
So
Since the area is in square feet, the rate of change is in ft^(2)/min.
So the rate of change is ft^(2)/min
Step-by-step explanation:
This is actually a very old riddle, but it is two guards and two doors life death .
So let's apply the same logic to this one.
You only meet one villager and you don't know if he is one of the ones who only tells the truth or always lies, to answer this riddle, the question is actually to an hypothetical third party, another villager, not present, this is a little convoluted so bear with me:
(Pointing to one of the roads): If I asked another villager if this road would lead me to the ruins, would he be correct?
If the villager is a truth one, the true-villager, would tell you that the liar-villager would say no (thus leading you to the jungle).
- Let's analyze this one, so the villager always tells the truth, and you happen to be pointing to the right direction (ruins), he is answering, that if you would ask another villager whether that is the correct road, that villager would say yes, since you are pointing at the right direction, a liar would tell you no, because the liar would point you to the other road as the correct (jungle), so the true-villager will say no
- If you happen to be pointing to the wrong direction (jungle), he is answering, that if you would ask another villager whether that is the correct road, that villager would say yes, since you are pointing at the wrong direction, the truth-villager would tell you no, because the liar would point you to the wrong road as the correct (jungle), so the villager will say no
Therefore, no matter what villager you run into, the question will always lead you to the jungle, and therefore you pick the other road.
<h3>
Answer: No, this isn't a function.</h3>
Why not? Focus on the two points (0,2) and (0,4)
We have the x value x = 0 show up twice. Any time x repeats itself like this, it leads to "not a function" as the result.
In other words, the input x = 0 leads to multiple outputs y = 2 and y = 4 at the same time. A function is only possible if every x input leads to exactly one y output.
If you are a visual learner, then plot all of the points on the same xy grid. Then notice how (0,2) and (0,4) fail the vertical line test to show we don't have a function.
Side note: The y values can repeat themselves in a function.
