A circle of radius 4 is centered at the point 56 Find a form

A circle of radius 4 is centered at the point (-5,6). Find a formula for f(q), the x-coordinate of the point P in the figure below (where q denotes the angle in the figure). (Use the variable q for the angle.)

Solution

Given r = 4,

P(x1,x2) = P(-5,6)

x = x1+rcos(q)

x = -5+4cos(q)

y = y1+rsin(q)

y = 6+4sin(q)

f(q)=(-5+4cos(q),6+4sin(q))