use
1. product of two lines perpendicular to each other is -1
2. angle between radius and tangent to the circle is 90
A is (-2,-4) and B is (sqrt 10, sqrt 10)
let tangent line from a l1 and from b l2
then l1 :
the gradient of radius from circle centre to a has (0--4)/(0--2)=2
from 1. the gradient of l1 is -0.5
therefore l1 : y=-0.5(x+2)-4=-0.5x-5
l2:
gradeint of radius from O to b has (sqrt 10)/(sqrt 10)=1
from 1. gradient of l2 is -1.
therefore l2: y= -(x-sqrt10)+sqrt10 = -x + 2sqrt10
C is where the 2 tangents meet so
-0.5x - 5 = -x + 2sqrt10
0.5x = 2sqrt10 + 5
x= 4sqrt10 + 10
sub x value into any line bc its on both lines
y=-0.5(4sqrt10+10)-5 = -2sqrt10-10
c(4sqrt10 + 10 , -2sqrt10-10)
graph is aut ism could be drawn for case A x coordinate is -4 and y coordinate is -2
but could simply know its wrong by the slope of 2 lines.
illusion 100