x² + y² = 25 and 4x² + 4y² = 25
a) x² + y² =25 is a cercle which is located at (0,0) with a radius = 5
b) 4x² + 4y² = 25. We can write it 4(x²+y²) = 25 OR x²+y² = 25/4
x²+y² = 25/4, this is a cercle which center is located at (0,0) with a radius =2.5
This transformation reduced the initial radius by half, from R = 5 to R = 2.5.
