Kris was asked to determine whether f ( x ) = x 3 − x f(x)=x 3 −xf, left parenthesis, x, right parenthesis, equals, x, cubed, minus, x is even, odd, or neither. Here is his work: Step 1: Find expression for f ( − x ) f(−x)f, left parenthesis, minus, x, right parenthesis f ( − x ) = ( − x ) 3 − ( − x ) = ( − 1 ) 3 ⋅ x 3 + x = − x 3 + x f(−x) =(−x) 3 −(−x) =(−1) 3 ⋅x 3 +x =−x 3 +x Step 2: Check if f ( − x ) f(−x)f, left parenthesis, minus, x, right parenthesis is equal to f ( x ) f(x)f, left parenthesis, x, right parenthesis or − f ( x ) −f(x)minus, f, left parenthesis, x, right parenthesis − x 3 + x −x 3 +xminus, x, cubed, plus, x is the same as − f ( x ) = − x 3 + x −f(x)=−x 3 +xminus, f, left parenthesis, x, right parenthesis, equals, minus, x, cubed, plus, x. Step 3: Conclusion f ( − x ) f(−x)f, left parenthesis, minus, x, right parenthesis is equivalent to − f ( x ) −f(x)minus, f, left parenthesis, x, right parenthesis, so f ff is odd. Is Kris' work correct? If not, what is the first step where Kris made a mistake? Choose 1 answer: Choose 1 answer: (Choice A) A Kris' work is correct. (Choice B) B Kris' work is incorrect. He first made a mistake in Step 1. (Choice C) C Kris' work is incorrect. He first made a mistake in Step 2. (Choice D) D Kris' work is incorrect. He first made a mistake in Step 3.
