Q.38 Evaluate limx→∞ x tan 1/x ∞ 1 0 −1

Q.38 Evaluate

limx→∞ x tan
1/x

  1. 1
  2. 0
  3. −1

Evaluate the Limit:
limx→∞ x tan(1/x)

Limits involving trigonometric functions are very common in calculus.
In this problem, we evaluate the limit:

Step-by-Step Solution

As x approaches infinity:

1/x → 0

Using the standard trigonometric limit:

limθ→0 (tan θ / θ) = 1

Rewrite the given expression:

x tan(1/x) = tan(1/x) / (1/x)

Now applying the limit:

limx→∞ tan(1/x) / (1/x) = 1

Correct Answer

Option (B): 1

Explanation of All Options

Option (A): ∞ — Incorrect
Although x increases without bound, tan(1/x) decreases to zero.
Their product approaches a finite value, not infinity.

Option (B): 1 — Correct
By using the identity limθ→0 (tan θ/θ) = 1,
the limit evaluates to exactly 1.

Option (C): 0 — Incorrect
The decrease in tan(1/x) is balanced by the increase in x, so the result
does not approach zero.

Option (D): -1 — Incorrect
The expression remains positive for large values of x, so the limit
cannot be negative.

Final Conclusion

The limit
limx→∞ x tan(1/x)
evaluates to:

1

 

Leave a Reply

Your email address will not be published. Required fields are marked *

Latest Courses