Please answer the following questions about the function f(x)=x2−46x2 Instructions:
• If you are asked for a function, enter a function.
• - If you are asked to find x - or y-values, enter either a number or a list of numbers separated by commas. If there are no solutions, enter None.
• - If you are asked to find an interval or union of intervals, use interval notation. Enter \{\} if an interval is empty.
• - If you are asked to find a limit, enter either a number, I for [infinity],−I for −[infinity], or DNE if the limit does not exist.

(a) Calculate the first derivative of f. Find the critical numbers of f, where it is increasing and decreasing, and its local extrema. f′(x)=−(x+2)2(x−2)248x