Find the equation to the cone whose vertex is the point (a,b,c) and whose generating lines

intersects the conic px2
+ qy2
= 1, z = 0.

3 answers

I think this will be a good place to start. The answer is given, and you can surely find your way there.

https://books.google.com/books?id=uwDfHbyl1IMC&pg=SL22-PA420&lpg=SL22-PA420&dq=Find+the+equation+to+the+cone+whose+vertex+is+the+point+(a,b,c)+and+whose+generating+lines+intersects+the+conic+px2+%2B+qy2&source=bl&ots=mE5TWchazF&sig=oOLM6wUqC9yTZcDi7LK36Dw63AI&hl=en&sa=X&ved=0ahUKEwi-wY3y8ebYAhVrjK0KHXUvDMQQ6AEIKTAA#v=onepage&q=Find%20the%20equation%20to%20the%20cone%20whose%20vertex%20is%20the%20point%20(a%2Cb%2Cc)%20and%20whose%20generating%20lines%20intersects%20the%20conic%20px2%20%2B%20qy2&f=false
Good
find the equation to the cone whose vertex is the point (a,b,c) and whose generating lines intersects the conic px2+by2+cz2=0