Given f of x equals inequality 2 cosine pi x comma for x is less than or equal to negative 1 inequality 2 over cosine pi x comma for x is greater than negative 1 What is the limit? limit x to negative 1 of f times x

For x approaching −1 from the left, use f(x) = 2 cos(πx), which approaches 2 cos(−π) = −2. From the right, use f(x) = 2 / cos(πx), which approaches 2 / cos(−π) = −2. Since both one-sided limits agree, the limit is −2, choice D.

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