The Solution.
The circle with a center at the origin implies that (a,b) = (0,0).
The equation of a circle is given by;
[tex]\begin{gathered} (x-a)^2+(y-b)^2=r^2 \\ \text{Where a=0, b=0 and r=7 units.} \end{gathered}[/tex]
Substituting the values above into the formula, we get
[tex]\begin{gathered} (x-0)^2+(y-0)^2=7^2 \\ x^2+y^2=49 \end{gathered}[/tex]
Step 3:
Presentation of the Answer.
Thus, the correct answer is option C / third option.
[tex]x^2+y^2=49[/tex]
