When the mobile phone asks questions, it is too focused and can only send 100 words, so the process cannot be completed. You can only say roughly: just prove that the vector product formed by the right focus and those two points is 0, and then work out what you need in turn (equation merging, etc.). , a little trouble). If you want to send me an email, I will send you ~O(∩_∩)O~ already sent it.