M7 · Expert
Calculus
Tangent line and stationary points
Formula
y = f(a) + f'(a)(x - a)
Rule
The derivative at a point is the slope of the tangent. Stationary points have f'(x) = 0.
Example
f(x) = x^2 has a minimum at x = 0.
Tip
Check the sign of the derivative either side to classify the point.
Learn this concept
Derivatives