MATH TASK

GROUP 1DIAN PERMANA

ANNISA INDAH REZA

DHIA ATIKAH ALIYYU

USWATUN HASANAH

WAN ELSA

The Circle Equation with Center P(a,b) and radius r !

The general equation distance is :

(x2-x1)2 + (y2-y1)2 = r2

So in the circle,

x1 = a y1 = b

x2 = x y2 = y

Then the circle equation become :

(x-a)2 + (y-b)2 = r2

P(a,b)

r

T(x,y)

y

x

Example . . .

1. Determine the circle equation with center P(-2,3) with the following requirement :

a. Passing through point Q(4,-1)

b. Meet an exatly one point X

c. Meet an exatly one point Y

Answers . . .

1. a. Q(4,-1)

P(2,-3)

(4-2)2 +(-3+1)2 = r2

(2)2 + (-2)2 = r2

8 = r2

(x-2)2 + (y+1)2 = 8

b. Meet an exatly one point X means r = b = 3

(x-2) + (y+1) = 9

c. Meet an exatly one point Y means r = a = 2

(x-2) + (y+1) = 4