Step 1: Determine the function and point of interest: We need to find the limit of the function tan(x) as x approaches −2π. The tangent function has a period of π, and it is known to have vertical asymptotes (where the function is undefined) at odd multiples of 2π. Since −2π is one such point, we expect the limit to not exist because the tangent function approaches negative infinity from the right and positive infinity from the left of −2π.
Step 2: Analyze the behavior of sine and cosine functions: To confirm our expectation, we can consider the behavior of the sine and cosine functions separately, as tan(x)=cos(x)sin(x). As x approaches −2π, sin(x) approaches −1 and cos(x) approaches 0. The cosine function approaches 0 through positive values from the right of −2π and through negative values from the left of −2π.
Step 3: Observe the sign change of cosine function: Since the cosine function changes sign around −(π)/(2), the tangent function will have opposite behaviors on either side of −(π)/(2). From the right, tan(x) will approach negative infinity, and from the left, it will approach positive infinity. This confirms that the limit does not exist because the left-hand limit and the right-hand limit are not equal.
Step 4: Determine the behavior of tangent function: Therefore, the correct answer is (D) The limit doesn't exist, because the function tan(x) does not approach a single finite value as x approaches −2π.