Q. Consider the equation x2−24x+y2+36y=−243. What is the radius of the circle in units?
Complete the square x-terms: Complete the square for the x-terms.x2−24x=(x−12)2−144
Complete the square y-terms: Complete the square for the y-terms.y2+36y=(y+18)2−324
Add constants: Add the constants from completing the square to the other side of the equation.(x−12)2−144+(y+18)2−324=−243(x−12)2+(y+18)2=−243+144+324(x−12)2+(y+18)2=225
Identify radius squared: Identify the radius squared from the standard form of the circle equation.The standard form is (x−h)2+(y−k)2=r2, where r is the radius.Here, r2=225
Calculate radius: Calculate the radius by taking the square root of r2.r=225r=15
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