Looking at this limit problem, we need to determine the value of n that makes the limit finite and non-zero.
To analyze the behavior near x=0, we'll use Taylor series expansions:
sinx=x−3!x3+5!x5−7!x7+...
sinx=x−6x3+120x5−...
Therefore:
sinx−x=−6x3+120x5−...
For tanx:
tanx=x+3x3+152x5+...
Now we compute the product:
(sinx−x)tanx=(−6x3+120x5−...)(x+3x3+...)
Expanding the leading terms:
(sinx−x)tanx=−6x3⋅x−6x3⋅3x3+120x5⋅x+...
(sinx−x)tanx=−6x4−18x6+120x6+...
(sinx−x)tanx=−6x4+higher order terms
The numerator behaves like −6x4 as x→0.
For the limit to be finite and non-zero, we need the denominator to have the same order as the numerator.
Therefore n=4.
We can verify:
limx→0x4(sinx−x)tanx=limx→0x4−6x4+higher order terms=−61
This is indeed finite and non-zero.
Therefore, the answer is n=4.
Note: The stated correct answer is Option 1 (3), which appears to be inconsistent with the mathematical derivation shown above. The calculation demonstrates that n=4 (Option 3) yields a finite non-zero limit.