Calculus 2 : Calculus II

Study concepts, example questions & explanations for Calculus 2

varsity tutors app store varsity tutors android store

Example Questions

Example Question #183 : Finding Limits And One Sided Limits

Evaluate the limit:

\(\displaystyle \lim_{n \to 2}\frac{n^2-n-2}{n^2-5n+6}\)

Possible Answers:

\(\displaystyle DNE\)

\(\displaystyle -3\)

\(\displaystyle -\infty\)

\(\displaystyle 0\)

\(\displaystyle \infty\)

Correct answer:

\(\displaystyle -3\)

Explanation:

The limiting situation in this equation would be the denominator. Plug the value that n is approaching into the denominator to see if the denominator will equal 0. In this question, the denominator will equal zero when n=2; so we try to eliminate the denominator by factoring. When the denominator is no longer zero, we may continue to insert the value of n into the remaining equation.

\(\displaystyle \lim_{n \to 2}\frac{n^2-n-2}{n^2-5n+6}=\lim_{n \to 2}\frac{(n-2)(n+1)}{(n-2)(n-3)}=\lim_{n \to 2}\frac{n+1}{n-3}=\frac{2+1}{2-3}=\frac{3}{-1}=-3\)

Example Question #231 : Calculus Ii

Evaluate the limit:

\(\displaystyle \lim_{n \to -3}\frac{n^2+2n-3}{n^2+4n+3}\)

Possible Answers:

\(\displaystyle 2\)

\(\displaystyle 0\)

\(\displaystyle -\infty\)

\(\displaystyle DNE\)

\(\displaystyle \infty\)

Correct answer:

\(\displaystyle 2\)

Explanation:

The limiting situation in this equation would be the denominator. Plug the value that n is approaching into the denominator to see if the denominator will equal 0. In this question, the denominator will equal zero when n=-3; so we try to eliminate the denominator by factoring. When the denominator is no longer zero, we may continue to insert the value of n into the remaining equation.

\(\displaystyle \lim_{n \to -3}\frac{n^2+2n-3}{n^2+4n+3}=\lim_{n \to -3}\frac{(n+3)(n-1)}{(n+3)(n+1)}=\lim_{n \to -3}\frac{n-1}{n+1}=\frac{-3-1}{-3+1}=\frac{-4}{-2}=2\)

Example Question #181 : Finding Limits And One Sided Limits

Evaluate the limit:

\(\displaystyle \lim_{n \to 1}n^2+3n+3\)

Possible Answers:

\(\displaystyle -\infty\)

\(\displaystyle DNE\)

\(\displaystyle 7\)

\(\displaystyle \infty\)

\(\displaystyle 0\)

Correct answer:

\(\displaystyle 7\)

Explanation:

There is no limiting situation in this equation (like a denominator) so we can just plug in the value that n approaches into the limit and solve:

\(\displaystyle \lim_{n \to 1}n^2+3n+3=(1)^2+3(1)+3=1+3+3=7\)

Example Question #231 : Calculus Ii

Evaluate the limit:

\(\displaystyle \lim_{n \to 2}n^2+\sqrt{n}\)

Possible Answers:

\(\displaystyle DNE\)

\(\displaystyle \infty\)

\(\displaystyle 0\)

\(\displaystyle 4+\sqrt{2}\)

\(\displaystyle -\infty\)

Correct answer:

\(\displaystyle 4+\sqrt{2}\)

Explanation:

There is no limiting situation in this equation (like a denominator) so we can just plug in the value that n approaches into the limit and solve:

\(\displaystyle \lim_{n \to 2}n^2+\sqrt{n}=(2)^2+\sqrt{2}=4+\sqrt{2}\)

Example Question #232 : Calculus Ii

Evaluate the limit:

\(\displaystyle \lim_{n \to -2}5n-4\)

Possible Answers:

\(\displaystyle 0\)

\(\displaystyle -\infty\)

\(\displaystyle DNE\)

\(\displaystyle -14\)

\(\displaystyle \infty\)

Correct answer:

\(\displaystyle -14\)

Explanation:

There is no limiting situation in this equation (like a denominator) so we can just plug in the value that n approaches into the limit and solve:

\(\displaystyle \lim_{n \to -2}5n-4=5(-2)-4=-10-4=-14\)

Example Question #233 : Calculus Ii

Evaluate the limit:

\(\displaystyle \lim_{n \to -3}15+5n\)

Possible Answers:

\(\displaystyle DNE\)

\(\displaystyle -3\)

\(\displaystyle 0\)

\(\displaystyle -\infty\)

\(\displaystyle \infty\)

Correct answer:

\(\displaystyle 0\)

Explanation:

There is no limiting situation in this equation (like a denominator) so we can just plug in the value that n approaches into the limit and solve:

\(\displaystyle \lim_{n \to -3}15+5n=15+5(-3)=15-15=0\)

Example Question #194 : Finding Limits And One Sided Limits

Evaluate the limit

\(\displaystyle \lim_{n \to 1}\frac{n^2-2n+1}{n^2-1}\)

Possible Answers:

\(\displaystyle 1\)

\(\displaystyle 0\)

\(\displaystyle -\infty\)

\(\displaystyle DNE\)

\(\displaystyle \infty\)

Correct answer:

\(\displaystyle 0\)

Explanation:

The limiting situation in this equation would be the denominator. Plug the value that n is approaching into the denominator to see if the denominator will equal 0. In this question, the denominator will equal zero when n=1; so we try to eliminate the denominator by factoring. When the denominator is no longer zero, we may continue to insert the value of n into the remaining equation.

\(\displaystyle \lim_{n \to 1}\frac{n^2-2n+1}{n^2-1}=\lim_{n \to 1}\frac{(n-1)(n-1)}{(n-1)(n+1)}=\lim_{n \to 1}\frac{n-1}{n+1}=\frac{1-1}{1+1}=\frac{0}{2}=0\)

Example Question #235 : Calculus Ii

Screen shot 2015 08 17 at 11.56.18 am

Given the above graph of \(\displaystyle f(x)\), what is \(\displaystyle \lim_{x\rightarrow 0^{+}}f(x)\)?

Possible Answers:

\(\displaystyle 1\)

\(\displaystyle \infty\)

Does Not Exist

\(\displaystyle 0\)

\(\displaystyle -\infty\)

Correct answer:

\(\displaystyle \infty\)

Explanation:

This particular question is asking us to find a one sided limit of the functions depicted by the graph. Since there is a plus sign in the exponent on the zero, this tells us that we are looking for a right handed limit. In other words, we will loook at the function values for x values that are slightly larger, or to the right of zero.

Examining the graph, we can observe that \(\displaystyle \lim_{x\rightarrow 0^{+}}f(x)=\infty\) as \(\displaystyle x\) approaches \(\displaystyle 0\) from the right.

Example Question #236 : Calculus Ii

Screen shot 2015 08 17 at 11.45.22 am

Given the above graph of \(\displaystyle f(x)\), what is \(\displaystyle \lim_{x\rightarrow 0^{-}}f(x)\)?

Possible Answers:

\(\displaystyle 1\)

\(\displaystyle 0\)

Does Not Exist

\(\displaystyle \infty\)

\(\displaystyle -\infty\)

Correct answer:

\(\displaystyle \infty\)

Explanation:

This particular question is asking us to find a one sided limit of the functions depicted by the graph. Since there is a negative sign in the exponent of the zero, this tells us that we are looking for a left handed limit. In other words, we will loook at the function values for x values that are slightly smaller, or to the left of zero.

Examining the graph, we can observe that \(\displaystyle \lim_{x\rightarrow 0^{-}}f(x)=\infty\) as \(\displaystyle x\) approaches \(\displaystyle 0\) from the left.

Example Question #234 : Calculus Ii

Evaluate the limit:

\(\displaystyle \lim_{n \to -1}n^3+n^4-n^5\)

Possible Answers:

\(\displaystyle \infty\)

\(\displaystyle 1\)

\(\displaystyle -\infty\)

\(\displaystyle 0\)

\(\displaystyle DNE\)

Correct answer:

\(\displaystyle 1\)

Explanation:

There is no limiting situation in this equation (like a denominator) so we can just plug in the value that n approaches into the limit and solve:

\(\displaystyle \lim_{n \to -1}n^3+n^4-n^5=(-1)^3+(-1)^4-(-1)^5=-1+1+1=1\)

Learning Tools by Varsity Tutors