Question

The equation of a circle whose center is at (1,2) and radius is 5 is (x + 1)² + (y + 2)² = 5 (x - 1)² + (y - 2)² = 25 (x - 1)² - (y - 2)² = 25

Answer 1

Answer:

The equation is (x - 1)² + (y - 2)² = 25

Step-by-step explanation:

Knowing that the equation of a circle is (view image, extracted https://www.google.com/search?q=ecuacion+circulo&rlz=1C1CHZL_esAR816AR816&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiMkvnGlcbjAhUbIrkGHX37AaMQ_AUIESgB&biw=1366&bih=608#imgrc=7ejmEpSWiG0WAM: )

Then, a and b represent the x and y value of the circle's center, and r^2, is the square of the radius.

Then, if we have that the center is (1,2) and the radius is 5:

$(x-1)^{2}(y-2)^{2} =5^{2} =25$

Answer 2

$\bf \textit{equation of a circle}\\\\ (x- h)^2+(y- k)^2= r^2 \qquad center~~(\stackrel{1}{ h},\stackrel{2}{ k})\qquad \qquad radius=\stackrel{5}{ r} \\\\\\\ (x-1)^2+(y-2)^2=5^2\implies (x-1)^2+(y-2)^2=25$