Answer:
A(r) = √2 * r
A(r) Domain is R { r ; r > 0}
Step-by-step explanation:
Diagonals of a square intercept each other in a 90° angle. The four triangles resulting from diagonal interception are equal and are isosceles triangles, with hipotenuse a side of the square
Therefore we apply Pythagoras theorem
Let x be side of square, and r radius of the circle, ( diagonals touch the circle) then
x² = r² + r²
x² = 2r²
x = √2 * r
Now Aea of square is :
A = L² where L is square side
A(r) = √2 * r
Domain of A(r) = R { r, r > 0}
The function is only shifted vertically up 3 :)
