Calculus 1 : Calculus

Study concepts, example questions & explanations for Calculus 1

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Example Questions

Example Question #11 : How To Graph Functions Of Points

Evaluate the limit: 

Possible Answers:

The limit does not exist at this point.

Correct answer:

Explanation:

To begin, we need L'Hopital's Rule for this problem which states that if you get  when you plug in the value into your function when evalutating the limit, you should take the derivative of both the numerator and the denominator and then try plugging in your value again. 

 

Since this is the case, we will take the derivative of the numerator and denominator.

To take the derivative of the numerator, we need the differentiation formulas for the trigonometric functions cosine and sine.

So, the derivative of the numerator is 

To find the derivative of the denominator, we again need the differentiation formula for cosine, as well as the chain rule.

In this problem,  and 

So, plugging these into the chain rule, we obtain:

Now let's put these expressions back into the numerator and denominator and again try to plug in our limit value:

Example Question #2591 : Calculus

Evaluate the limit: 

Possible Answers:

The limit does not exist.

Correct answer:

Explanation:

To solve this problem, we need L'Hopital's Rule, the derivative of the natural logarithm, the chain rule, the power rule, and the derivative of a constant.

Notice that if we plug in our  value into the function, we obtain a value of  .

L'Hopital's Rule, which states that if you plug in your limit value and obtain , you should take the derivative of the numerator and denominator and try plugging in your limit value again.

So we will take the derivative of the numerator and denominator.

For the numerator, we need the chain rule,the derivative of the natural logarithm, the derivative of a constant, and the power rule, which state:

 

For the numerator,  and .

Applying the chain rule to this expression yields:

To find the derivative of the denominator, we need the power rule and the derivative of a constant.

So now we have:

Example Question #11 : How To Graph Functions Of Points

Find the x-coordinate of the critical points of .

Possible Answers:

None of the other answers.

Correct answer:

Explanation:

We need to differentiate term by term, applying the power rule,

This gives us

The x-coordinate of the critical points are the points where the derivative equals 0. To find those, we can use the quadratic formula:

 

Example Question #1564 : Functions

Find the x value of the critical points of .

Possible Answers:

Correct answer:

Explanation:

We need to differentiate term by term, applying the power rule,

This gives us

The critical points are the points where the derivative equals 0. To find those x values, we can use the quadratic formula:

 

Example Question #1565 : Functions

Find the x values of the critical points of .

Possible Answers:

None of the other answers.

Correct answer:

Explanation:

We need to differentiate term by term, applying the power rule,

This gives us

The critical points are the points where the derivative equals 0. To find those, we can use the quadratic formula:

 

 

Example Question #12 : Other Points

Find the x values for critical points of .

Possible Answers:

None of the other answers.

Correct answer:

Explanation:

We need to differentiate term by term, applying the power rule,

This gives us

The critical points are the points where the derivative equals 0. To find those, we can use the quadratic formula:

 

Example Question #1 : Intervals

Find the interval(s) where the following function is decreasing. Graph to double check your answer.

Possible Answers:

Always

Never

Correct answer:

Explanation:

To find when a function is decreasing, you must first take the derivative, then set it equal to 0, and then find between which zero values the function is negative.

First, take the derivative:

Set equal to 0 and solve:

Now test values on all sides of these to find when the function is negative, and therefore decreasing. I will test the values of -6, 0, and 2.

Since the only value that is negative is when x=0, the interval is only decreasing on the interval that includes 0. Therefore, our answer is:

 

 

 

 

Example Question #2 : Intervals

Find the interval(s) where the following function is decreasing. Graph to double check your answer.

Possible Answers:

Never

Always

Correct answer:

Explanation:

To find when a function is decreasing, you must first take the derivative, then set it equal to 0, and then find between which zero values the function is negative.

First, take the derivative:

Set equal to 0 and solve:

Now test values on all sides of these to find when the function is negative, and therefore decreasing. I will test the values of 0, 2, and 10.

Since the only value that is negative is when x=0, the interval is only decreasing on the interval that includes 2. Therefore, our answer is:

Example Question #3 : Intervals

Is  increasing or decreasing on the interval ?

Possible Answers:

The function is neither increasing nor decreasing on the interval .

Decreasing, because the first derivative is positive on the interval .

Decreasing, because the first derivative of  is negative on the function .

Increasing, because the first derivative is positive on the interval .

Increasing because the second derivative is positive on the interval .

Correct answer:

Decreasing, because the first derivative of  is negative on the function .

Explanation:

To find the an increasing or decreasing interval, we need to find out if the first derivative is positive or negative on the given interval. So, find  by decreasing each exponent by one and multiplying by the original number.

Next, we can find  and  and see if they are positive or negative.

Both are negative, so the slope of the line tangent to  is negative, so  is decreasing.

Example Question #1 : How To Find Decreasing Intervals By Graphing Functions

Is  increasing or decreasing on the given interval? How do you know?

Possible Answers:

Decreasing, because  is negative on the interval .

Decreasing, because  is negative on the interval .

Increasing, because  is positive on the interval .

There is not enough information to tell whether  is increasing or decreasing on the interval .

Increasing, because  is positive on the interval .

Correct answer:

Increasing, because  is positive on the interval .

Explanation:

Recall that a function is increasing at a point if its first derivative is positive, and a function is decreasing if its first derivative is negative at that point. Therfore, we should start by finding f'(x). However, I will start by combining like terms and putting f(x) in standard form:

Next, plug in each of our endpoints to see what the sign of f'(x) is.

So f'(x) is positive on the given interval, so we know that f(x) is increasing on the given interval.

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