3. What are the coordinates of the points of tangency of the two tangent lines through the point (1,1) each tangent to the circle x^2+y^2=1?

Respuesta :

Answer:[tex]y+x=2[/tex]    

Step-by-step explanation:

Given

equation of circle [tex]x^2+y^2=1[/tex]

Equation of tangent passing through (1,1)

Slope of tangent is given by differentiating equation of circle

[tex]2x+2y\frac{\mathrm{d} y}{\mathrm{d} x}=0[/tex]

[tex]\frac{\mathrm{d} y}{\mathrm{d} x}=\frac{-x}{y}[/tex]

at [tex](x,y)=(1,1)[/tex]

[tex]\frac{\mathrm{d} y}{\mathrm{d} x}=\frac{-1}{1}[/tex]

Equation of line with slope

[tex]m=\frac{y-y_0}{x-x_0}[/tex]

[tex]-1=\frac{y-1}{x-1}[/tex]

[tex]y+x=2[/tex]