It is known that the area of a square is the square of X - 2aX + a (x is greater than 0, a is less than 0), and the algebraic expression of the side length of the square is obtained

It is known that the area of a square is the square of X - 2aX + a (x is greater than 0, a is less than 0), and the algebraic expression of the side length of the square is obtained

S=x²-2ax+a²
=(x-a)²
∵x>0,a0
Square side length = √ s = x-a

If the area of a square is 9x2 + 6x + 1 (x > 0), then the side length is______ ．

∵ 9x2 + 6x + 1 = (3x + 1) 2, the side length of the square is (3x + 1)

A square has an area of 10. Find the area of a circle whose diameter is the side length of the square. (the result is accurate to 0.01)

Let the side length of a square be a, s = A & sup2; = 10, so a = √ 10
The area of a circle with square side length as diameter is π * (A / 2) & sup2; = π * 2.5 ≈ 7.85