1. f : X → Y is continuous bijection,
Ⅰ. If X is compact then Y is compact.
Ⅱ. If X is Hausdorff space then Y is Hausdorff space.
Ⅲ. If X is compact and Y is Hausdorff space, then f−1 exist.
Which of them are correct?
不会。。。连续双射能保持哪些性质?
46. There is a cube with edge n, and there are balls contained completely in the ball with the center at the integral coordinate and the radius 12, try to get the limit of the ratio of the total volume of the balls to the volume of the cube as n is towards infinity.
没看懂题,“with the center at the integral coordinate”什么意思?