Problem statement: We need to find the limit of the function cos(x) as x approaches 4π. The limit of a function at a point is the value that the function approaches as the input approaches that point. For trigonometric functions like cosine, we can directly substitute the value into the function if the function is continuous at that point and the point is within the domain of the function.
Step 1: Function limit definition: Since the cosine function is continuous everywhere, and 4π is within its domain, we can substitute x=4π directly into the function to find the limit.
Step 2: Substituting x into the function: Substitute x=4π into cos(x):limx→4πcos(x)=cos(4π)
Step 3: Evaluating the function: We know from trigonometry that cos(4π) is equal to 22.limx→4πcos(x)=22
Step 4: Trigonometric identity: Therefore, the limit of cos(x) as x approaches 4π is 22, which corresponds to choice (C).
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