All Precalculus Resources
Example Questions
Example Question #41 : Introductory Calculus
Find the following limit:
To solve, simply realize you are dealing with a limit whose numerator and demominator have the same max power. Thus the limit is simply the division of their coefficient.
Example Question #1 : Determine If A Function Is Continuous Using Limits
Find the domain where the following function is continuous:
The function in the numerator factors to:
so if we cancel the x+3 in the numerator and denominator we have the same function but it is continuous. The gives us a hole at x=-3 so our function is not continuous at x=-3.
Example Question #1 : Determine If A Function Is Continuous Using Limits
What are the discontinuities in the following function and what are their types?
Since the factor is in the numerator and the denominator, there is a removable discontinuity at . The function is not defined at , but function would move towards the same point for the resultant function .
Since the factor cannot be factored out, there is an infinite discontinuity at . The denominator will get very small and the numerator will move toward a fixed value.
There is no discontinuity at all at . The function simply evaluates to zero at this point.
Example Question #662 : Pre Calculus
Determine if the function is continuous at using limits.
No, it is not continuous because the lefthand and righthand limits do not equal the value of the function at 0.
Yes, it is continuous because the lefthand and righthand limits are equal.
Yes, it is continuous because the righthand and lefthand limits are equal to the actual value of the function.
No, it is not continuous because the lefthand limit does not match the righthand limit.
Yes, it is continuous because the righthand and lefthand limits are equal to the actual value of the function.
In order to determine if a function is continuous at a point three things must happen.
1) Taking the limit from the lefthand side of the function towards a specific point exists.
2) Taking the limit from the righthand side of the function towards a specific point exists.
3) The limits from 1) and 2) are equal and equal the value of the original function at the specific point in question.
In our case,
1)
2)
3)
Because all of these conditions are met, the function is continuous at 0.
Example Question #1 : Determine If A Function Is Continuous Using Limits
Determine if is continuous on all points of its domain.
No, it is not continuous because the lefthand and righthand limits do not equal the value of the function at 0.
No, it is not continuous because the lefthand limit does not match the righthand limit.
Yes, it is continuous because the lefthand and righthand limits are equal.
Yes, it is continuous because the righthand and lefthand limits are equal to the actual values of the function.
Yes, it is continuous because the righthand and lefthand limits are equal to the actual values of the function.
First, find that at any point where , .
Then find that
and .
As these are all equal, it can be determined that the function is continuous on all points of its domain.
Example Question #5 : Determine If A Function Is Continuous Using Limits
Let . Determine if the function is continuous using limits.
As approaches , the function approaches , which is undefined. However, if we factor , we get:
The factors in the numerator and denominator cancel out, leaving .
Therefore, our function is continuous at all values of from .
Example Question #1 : Rate Of Change Problems
Find the average rate of change of the function over the interval from to .
The average rate of change will be found by .
Here, , and .
Now, we have .
Example Question #2 : Rate Of Change Problems
Let a function be defined by .
Find the average rate of change of the function over .
We use the average rate of change formula, which gives us .
Now , and .
Therefore, the answer becomes .
Example Question #2 : Derivatives
Suppose we can model the profit, , in dollars from selling items with the equation .
Find the average rate of change of the profit from to .
We need to apply the formula for the average rate of change to our profit equation. Thus we find the average rate of change is .
Since , and , we find that the average rate of change is .
Example Question #3 : Derivatives
Let the profit, , (in thousands of dollars) earned from producing items be found by .
Find the average rate of change in profit when production increases from 4 items to 5 items.
Since , we see that this equals. Now let's examine . which simplifies to .
Therefore the average rate of change formula gives us .