Trap an oscillating expression between two bounds with the same limit. 60 problems with worked solutions; in 60 of them every
equation is proved by a computer algebra system.
16 worked problems
Try each one before opening the solution. Every line is labeled with what checked it. How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( -1 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Use the squeeze theorem to find \( \displaystyle \lim_{x \to 0} x^{2} \sin{\left(\frac{4}{x} \right)} \).
Since −1 ≤ sin(·) ≤ 1, the expression lies between -x**2 and x**2.
Reviewed
\[ \lim_{x \to 0}\left(- x^{2}\right) = 0 \]
The lower bound's limit.✓ Proved
\[ \lim_{x \to 0} x^{2} = 0 \]
The upper bound's limit, the same.✓ Proved
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Use the squeeze theorem to find \( \displaystyle \lim_{x \to 0} x^{2} \cos{\left(\frac{2}{x} \right)} \).
Since −1 ≤ cos(·) ≤ 1, the expression lies between -x**2 and x**2.
Reviewed
\[ \lim_{x \to 0}\left(- x^{2}\right) = 0 \]
The lower bound's limit.✓ Proved
\[ \lim_{x \to 0} x^{2} = 0 \]
The upper bound's limit, the same.✓ Proved
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 3 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 3 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Both bounds tend to the same value, so the expression trapped between them does too.
Reviewed
Answer \( 0 \)
✓ Nihil obstat Lines: 2 proved, 2 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify