Equation of a circle Quiz

1. What is the centre of $(x+1)^2+(y-5)^2=9$?

• A. $(1,-5)$
• B. $(-1,5)$
• C. $(1,5)$
• D. $(-1,-5)$

2. What is the radius of $x^2+y^2=49$?

• A. $\sqrt7$
• B. $24.5$
• C. $49$
• D. $7$

3. Which is the equation of the circle with centre $(2,-3)$ and radius $4$?

• A. $(x+2)^2+(y-3)^2=16$
• B. $(x-2)^2+(y+3)^2=4$
• C. $(x-2)^2+(y+3)^2=16$
• D. $(x-2)^2+(y-3)^2=16$

4. Where does $(4,0)$ lie relative to $(x-1)^2+(y-4)^2=25$?

• A. On the circle
• B. Inside the circle
• C. Outside the circle
• D. At the centre

5. Find the centre and radius of $x^2+y^2-6x+2y-6=0$.

• A. $(-3,1)$, radius $4$
• B. $(3,-1)$, radius $4$
• C. $(3,-1)$, radius $\sqrt{6}$
• D. $(3,-1)$, radius $16$