There's no diagram here so I can't be specific, but I've attached an image.
Answer:
The answer is D, 
Step-by-step explanation:
By graphing each one in a graphing tool like Desmos, you can determine which one it is.
If your looking for an actual explanation on how it is found, I can't really help you on that one.
Answer:
a
Step-by-step explanation:
I think so..