If the line y = x touches the curve y = x2 + bx + c at a point (1, 1) then
Given that line y = x touches the curve y = x2 + bx + c at a point (1, 1)
Slope of line = 1
Slope of tangent to the curve = 1
⇒ 2x+b = 1
⇒ 2 + b = 1
⇒ b = -1
Putting this and x =1 and y = 1 in the equation of the curve,
1 = 1 -1 + c
⇒ c = 1