Find the equation of the tangent line to the curve y = x2 – 2x + 7 which is
parallel to the line 2x – y + 9 = 0
finding the slope of the tangent by differentiating the curve
m(tangent) = 2x – 2
equation of tangent is given by y – y1 = m(tangent)(x – x1)
now comparing the slope of a tangent with the given equation
m(tangent) = 2
2x – 2 = 2
x = 2
since this point lies on the curve, we can find y by substituting x
y = 22 – 2 × 2 + 7
y = 7
therefore, the equation of the tangent is
y – 7 = 2(x – 2)