Question

What is the length of the radius of a circle with a center at 2 – i and a point on the circle at 8 + 7i?

Answer 1

10

Explanation:

We need to find a distance between this to points.

D=√((x2-x1)²+(y2-y1)²)

For complex plain, the real part of the complex number plays a role of x,

and number of an imaginary part plays a role of y.

So,

D=√((8-2)² +(7+1)²)√ = √(36+64)=√(100)=10

Answer 2

We need to find a distance between this to points.
D=√((x2-x1)²+(y2-y1)²)

For complex plain, the real part of the complex number plays a role of x,
and number of an imaginary part plays a role of y.
So,
D=√((8-2)² +(7+1)²)√ = √(36+64)=√(100)=10
Answer is D.10