Evaluate the limit as x approaches 0 of (e^(x2x^2) - cos(x)) / (x2x^2).

Answer: 32\frac{3}{2}

Step-by-step solution

Step 1: Check for indeterminate form

First, we substitute x=0x = 0 into the numerator and the denominator to check the form of the limit. We find that both the numerator and the denominator approach 0, resulting in an indeterminate form of 00\frac{0}{0}. This indicates that L'Hôpital's Rule can be applied.

Step 2: Apply L'Hôpital's Rule

Since the limit is in the indeterminate form 00\frac{0}{0}, we can apply L'Hôpital's Rule. This rule states that if lim⁡x→cf(x)g(x)\lim_{x \to c} \frac{f(x)}{g(x)} is of the form 00\frac{0}{0} or ∞∞\frac{\infty}{\infty}, then lim⁡x→cf(x)g(x)=lim⁡x→cf′(x)g′(x)\lim_{x \to c} \frac{f(x)}{g(x)} = \lim_{x \to c} \frac{f'(x)}{g'(x)} provided the latter limit exists.

Step 3: Differentiate numerator and denominator

We differentiate the numerator and the denominator. The derivative of ex2e^{x^2} is ex2⋅(2x)e^{x^2} \cdot (2x) by the chain rule, and the derivative of - cos⁡(x)\cos(x) is -(- sin⁡(x)\sin(x)) = sin⁡(x)\sin(x). The derivative of x2x^2 is 2x.

Step 4: Substitute derivatives and re-evaluate limit

Now we substitute the derivatives back into the limit expression. We then try to evaluate the limit again by substituting x=0x = 0. We find that the numerator becomes 2(0) e02+sin⁡(0)=0+0=0e^{0^2} + \sin(0) = 0 + 0 = 0, and the denominator becomes 2(0) = 0. This is still an indeterminate form 00\frac{0}{0}, so we must apply L'Hôpital's Rule again.

Step 5: Apply L'Hôpital's Rule again

We differentiate the new numerator and denominator. For 2xex22xe^{x^2}, we use the product rule: 2ex2+2x(ex2⋅2x)=2ex2+4x2ex22e^{x^2} + 2x(e^{x^2} \cdot 2x) = 2e^{x^2} + 4x^2e^{x^2}. The derivative of sin⁡(x)\sin(x) is cos⁡(x)\cos(x). The derivative of 2x is 2.

Step 6: Evaluate the final limit

Finally, we substitute x=0x = 0 into the expression with the second derivatives. The numerator becomes 2e0+4(0)2e0+cos⁡(0)=2(1)+0+1=32e^0 + 4(0)^2e^0 + \cos(0) = 2(1) + 0 + 1 = 3. The denominator is 2. Thus, the limit is 32\frac{3}{2}.

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