3. a) Determine whether the point A(2, 6) lies on the circle defined by

x2+ y2 = 40.

b) Find an equation for the radius from the origin O to point A.

a) To determine whether the point A(2, 6) lies on the circle defined by x^2 + y^2 = 40, we can substitute the x and y coordinates of A into the equation and check if the equation holds true.

Substituting x = 2 and y = 6 into the equation,

2^2 + 6^2 = 40
4 + 36 = 40

40 = 40

The equation holds true, so the point A(2, 6) lies on the circle defined by x^2 + y^2 = 40.

b) To find the equation for the radius from the origin O to point A, we can use the distance formula. The distance between two points (x1, y1) and (x2, y2) is given by:

Distance = √((x2 - x1)^2 + (y2 - y1)^2)

In this case, the origin O is the point (0, 0) and point A is (2, 6). Substituting these values into the distance formula,

Distance = √((2 - 0)^2 + (6 - 0)^2)
= √(2^2 + 6^2)
= √(4 + 36)
= √40

Therefore, the equation for the radius from the origin O to point A is √40.

a) To determine whether the point A(2, 6) lies on the circle defined by x^2 + y^2 = 40, we need to substitute the x and y values of point A into the equation and see if it satisfies the equation.

Substituting x = 2 and y = 6 into the equation, we get:

2^2 + 6^2 = 40
4 + 36 = 40

As 40 = 40, the equation is satisfied. Hence, the point A(2, 6) lies on the circle defined by x^2 + y^2 = 40.

b) To find an equation for the radius from the origin O to point A, we can use the distance formula.

The distance formula is given by:
d = sqrt((x2 - x1)^2 + (y2 - y1)^2)

Let O(0, 0) be the origin and A(2, 6) be the point.

Using the distance formula, the equation for the radius from O to A is:

r = sqrt((2 - 0)^2 + (6 - 0)^2)
r = sqrt(2^2 + 6^2)
r = sqrt(4 + 36)
r = sqrt(40)

Therefore, the equation for the radius from the origin O to point A is r = sqrt(40).