assume the point is in the fourth quadrant

Question

Assume the point (x,−22/25) is on the unit circle in the fourth quadrant.

x=

Answer 1

(x-h)^2+(y-k)^2=r^2 where (h,k) is the center of the circle and r is the radius

because it's the unit circle (h,k)=(0,0) and r=1

therefor we have x^2+y^2=1

y=-22/25 so substitute this for y and solve for x

x^2+(-22/25)^2=1

x^2+(484/625)=1

x^2=1-(484/625)

x^2=(141/625)

take the square root of both sides

x=sqrt(141/625)

x=sqrt(141)/sqrt(625)

x=sqrt(141)/25