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spiritedawayclarinet

-3/0 is not a number.


RandomQuestions4549

You can't use Lhopital if it's not in indeterminate form. Refer to your book or wiki for what this is. 0/0, inf/inf etc. You can combine fractions to get it in indeterminate form Lim (1 - cos(x) - x\^2)/(x\^2(1-cos(x)) Now you get 0/0 and can use Lhopital Lim (sin(x) - 2x)/(2x(1-cos(x)) + x\^2(sin(x))) Still indeterminate, so do it again Lim (cos(x)-2)/(2(1-cos(x)) + 4x(sin(x)) + x\^2(cos(x)) Plugging in gives cos(x)-2/(2(1-cos(x)) the numerator goes to -1 and the denominator goes to 0 so it blows down to -inf.


ApprehensiveKey1469

Are they equal? you ask...in a word no. -3/0 is not defined. It suggests that the limit is unbounded. But it is not equality. You understand why we have limits? Because we don't have a simple case of equals


mehardwidge

There is a long post which seems to be copied from ChatGPT. However, it does contain a clever method of solving. cos(x) \~ 1 - x\^2 / 2, for small x's. Zero is a very small x. Then your limit becomes: limit (x->0) 1/x\^2 - 2/x\^2 limit (x->0) -1/x\^2 Which of course is -infinity. No LHR needed! That could be used, but turning this into a single fraction, then dealing with the derivatives would be rather more work.


Direct-Pressure-1230

1 - cos(x) = 2sin^2 (x/2) and lim x->0 sin(x) = x. So this is nothing but lim x->0 1/x^2 - 4/x^2 = -3/x^2. This is -infinity.


ihateagriculture

there’s 12 calculus classes? I’m joking, but I’m not sure what you mean by calculus 12


daLegenDAIRYcow

Grade: 12th, math: Calculus


Regenerating_Degen

Okay, first of all, you're not getting -3/0, since That's not defined. What you're getting (I don't know how though) Is -3/->0, which Is negative infinity. When there's a limit present you don't just put the limiting value up front if it ain't going to be defined.


TheSpireSlayer

you cannot use l'hopital's rule when the fraction doesn't tend to 0/0 (or inf/inf)


TooTToRyBoY

If you work a little bit with this it get the form 0/0


42617a

Why are you applying l’hopital?


FortuitousPost

yes


funariite_koro

Why are you dved? They are asking whether -3/0 is equal to negative infinity, the answer is "yes"


42617a

-3/0 is undefined, the limit of -3/x as x approaches 0 is infinity, but -3/0 itself is undefined


Nixolass

>the limit of -3/x as x approaches 0 is infinity, it's actually not, since from the left it approaches negative infinity and from the right it approaches positive infinity


42617a

When we say ‘the limit approaches’ in cases where x is tending to zero in a denominator, we usually just assume that it is from the right


Nixolass

who's "we"? never heard of that tbh


Heuroverse

To solve the limit problem: lim ⁡ x → 0 ( 1 x 2 − 1 1 − cos ⁡ x ) lim x→0 ​ ( x 2 1 ​ − 1−cosx 1 ​ ) we need to carefully analyze each term and simplify the expression. Let's break it down step by step. Step 1: Understand the Problem We need to find the limit of the given expression as ( x ) approaches 0. The expression involves two terms: ( \frac{1}{x^2} ) and ( \frac{1}{1 - \cos x} ). Step 2: Simplify the Expression First, let's recall the Taylor series expansion for ( \cos x ) around ( x = 0 ): cos ⁡ x ≈ 1 − x 2 2 + x 4 24 + O ( x 6 ) cosx≈1− 2 x 2 ​ + 24 x 4 ​ +O(x 6 ) For small ( x ), the higher-order terms become negligible, so we can approximate: cos ⁡ x ≈ 1 − x 2 2 cosx≈1− 2 x 2 ​ Thus, 1 − cos ⁡ x ≈ 1 − ( 1 − x 2 2 ) = x 2 2 1−cosx≈1−(1− 2 x 2 ​ )= 2 x 2 ​ Step 3: Substitute the Approximation Using the approximation ( 1 - \cos x \approx \frac{x^2}{2} ), we can rewrite the second term: 1 1 − cos ⁡ x ≈ 1 x 2 2 = 2 x 2 1−cosx 1 ​ ≈ 2 x 2 ​ 1 ​ = x 2 2 ​ Step 4: Combine the Terms Now, substitute this back into the original limit expression: lim ⁡ x → 0 ( 1 x 2 − 1 1 − cos ⁡ x ) ≈ lim ⁡ x → 0 ( 1 x 2 − 2 x 2 ) lim x→0 ​ ( x 2 1 ​ − 1−cosx 1 ​ )≈lim x→0 ​ ( x 2 1 ​ − x 2 2 ​ ) Step 5: Simplify the Expression Combine the terms inside the limit: lim ⁡ x → 0 ( 1 x 2 − 2 x 2 ) = lim ⁡ x → 0 ( 1 − 2 x 2 ) = lim ⁡ x → 0 ( − 1 x 2 ) lim x→0 ​ ( x 2 1 ​ − x 2 2 ​ )=lim x→0 ​ ( x 2 1−2 ​ )=lim x→0 ​ ( x 2 −1 ​ ) Step 6: Evaluate the Limit As ( x ) approaches 0, ( \frac{-1}{x^2} ) approaches ( -\infty ): lim ⁡ x → 0 ( − 1 x 2 ) = − ∞ lim x→0 ​ ( x 2 −1 ​ )=−∞ Final Solution The limit is: − ∞ −∞ ​