We have the equation:

By arranging this equation in terms of x and y, we have:

By using the method of completing the square, we have:

The center of this circle is:

So the equation that fulfills the statement is:

Finally, the right answer is c)
Sec is 1/cos so sec -120 is 1/cos -120 which is -2
Answer:
Sophia is 17 years old. Sophia's brother is 11 years old.
Step-by-step explanation: