Write the equation of the circle with center (0, 0) and (3, 6) a point on the circle.

Hey there :)

We know that the equation of a circle is;
( x - h )² + ( x - k )² = ( radius )²

We are given:
( 3 , 6 ) = ( x , y )   ( point on the circle )
( 0 , 0 ) = ( h , k )   ( centre )
r² = ?

Apply to the formula and find r:
( 3 - 0 )² + ( 6 - 0 )² = r²
( 3 )² + ( 6 )² = r²
9 + 36 = r²
45 = r²
45 = r²

Therefore, the equation of the circle will be:
( x - 0 )² + ( y - 0 )² = 45

x² + y² = 45   →   Your answer