Power function image: ① when a≤- 1 and a is odd, the function is a subtraction function in the first and third quadrants; (2) when a≤- 1 and a is even, the function is increasing function in the second quadrant and subtraction in the first quadrant; ③ When a=0 and x is not 0, the function image is parallel to the x axis, and y= 1, but. A< is at 1, the function is increasing function ⑤ When a≥ 1 and a is odd, the function is odd function ⑤ When a≥ 1 and a is even, the image with even power function is only the fourth quadrant.