Joel L. answered 03/30/22
MS Mathematics coursework with 20+ Years of Teaching Experience
Given: f(x)=x2-3x+1 at x=1
f(1) = 12 -3(1) + 1 = -1
This means the point of tangency is at (1,-1)
We know that the slope-intercept form of a linear equation is y= mx + b, first find the slope using derivatives:
f'(x) = 2x - 3
f'(1) = 2(1) - 3 = -1
Therefore the slope (m) is -1
m = -1
Using the point of tangency and the slope, we can have the linear equation in point slope form
y - y1 = m (x - x1)
where: m = -1 and (x1,y1) = (1,-1)
y - (-1) = -1(x - 1)
y + 1 = -x + 1
Subtract 1 on both sides of the equation, we'll have the slope intercept form of the equation of the tangent line:
y = -x