f(x)=−x 2
+7x−7 f ′
(x)= (Type an expression using x as the variable.) Select the correct answer below and, if necessary, fill in the answer box to complete your choice. A. f ′
(1)= (Type an integer or a simplified fraction.) B. The derivative does not exist. Select the correct answer below and, if necessary, fill in the answer box to complete your choice. A. f ′
(2)= (Type an integer or a simplified fraction.) B. The derivative does not exist. Select the correct answer below and, if necessary, fill in the answer box to complete your choice. A. f ′
(3)= (Type an integer or a simplified fraction.)