Question

centre of a circle is at (-1,3) and one end of a diameter has co-ordinates (2,5). then co-ordinates of other end of circle is

• A. (-4,1)
• B. (1,-4)
• C. (4,-1)
• D. none of these

Answer 1

Answer: (A)

(-4,1)

$LetthecoordinatesbeQ(x_1,y_1)$

Given center $(-1,3)$ and one end of a diameter is $(2,5)$

Center will be the mid point of diameter

Let $(x,y)=(-1,3),(x_2,y_2)=(2,5)$

$Bymidpointformula$

$x=\frac{x_1+x_2}{2}y=\frac{y_1+y_2}{2}$

$-1=\frac{x_1+2}{2}3=\frac{y_1+5}{2}$

$x_1=-4y_1=1$

$\therefore Q(x_1,y_1)=Q(-4,1)$