Identify Form of Limit: Identify the form of the limit.We need to determine the form of the limit as x approaches infinity for the function e4x−1−4xx2. By substituting x with infinity, we can see that the numerator grows as a polynomial of degree 2, while the denominator grows exponentially. Since exponential functions grow faster than polynomial functions, we expect the limit to be 0. However, we need to confirm this by further analysis.
Apply L'Hôpital's Rule: Apply L'Hôpital's Rule.Since the limit as x approaches infinity seems to be of the form [∞/∞], we can apply L'Hôpital's Rule. This rule states that if the limit of f(x)/g(x) as x approaches a value is [∞/∞] or [0/0], then the limit is the same as the limit of the derivatives of the numerator and the denominator. We will differentiate the numerator and the denominator separately.
Differentiate Numerator: Differentiate the numerator.The derivative of x2 with respect to x is 2x.
Differentiate Denominator: Differentiate the denominator.The derivative of e4x−1−4x with respect to x is 4e4x−4.
Apply L'Hôpital's Rule with Derivatives: Apply L'Hôpital's Rule by substituting the derivatives.Now we have a new limit to evaluate: limx→∞4e4x−42x. We can simplify this by dividing both the numerator and the denominator by 2, which gives us limx→∞2e4x−2x.
Evaluate New Limit: Evaluate the new limit.As x approaches infinity, the numerator x grows linearly, while the denominator 2e(4x)−2 still grows exponentially. Therefore, the limit of 2e(4x)−2x as x approaches infinity is 0.
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