Question

What is the radius of the following circle?

Answer 1

Radius = 1

Explanation:

It is given that equation of a circle is x² + y² = 1

Points to remember

Equation of a circle with center(h, k) and radius r is given by,

(x - h)² + (y - k)² = r²

To find the radius of circle

Compare the two equations

x² + y² = 1 and (x - h)² + (y - k)² = r²

we get the center is (0, 0)

therefore we can write

r² = 1

r = 1

Therefore radius r = 1

Answer 2

The radius is: 1

Explanation:

The equation of a circle in center-radius form is:

`(x - h)^2 + (y - k)^2 = r^2`

Where the center is at the point (h, k) and the radius is "r".

Given the equation of the circle:

`x^2+y^2=1`

You can identify that:

`r^2=1`

Then, solving for "r", you get that the radius of the circle is:

`r=√(1)\\\\r=1`