Question 637443
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
y = x^2 – 6x + 9     
y ' = {{{2x - 6}}}  when x = 2  &#8658;   y' = -2, the slope m of the tangent line
   y = mx + b
  y = -2x + b   ||Using Pt(2,1) to find b   |Note: when x = 2, y = 1   
  1 = -4 + b
  5 = b
  y = -2x + 5
{{{drawing(300,300,   -6, 6, -6, 6,  blue(line(3,6,3,-6))  , grid(1),
circle(2, 1,0.3),
graph( 300, 300, -6, 6, -6, 6,0,-2x+5,x^2 -6x + 9))}}}