Derivatives & Differentiation
Tangent Line Equation
The equation of the tangent line at point (x₀, f(x₀)) is:
Where f'(x₀) is the derivative at x₀.
Understanding Derivatives
The derivative f'(x) represents the instantaneous rate of change of f(x) at point x. Geometrically, it's the slope of the tangent line to the curve at that point.
Integrals & Area Under Curves
Riemann Sum
A Riemann sum approximates the definite integral by dividing the area into rectangles:
where \(\Delta x = \frac{b-a}{n}\) and \(x_i^*\) is a sample point in the i-th subinterval.
The Fundamental Theorem of Calculus connects differentiation and integration:
where F is an antiderivative of f (i.e., F' = f).
FTC Part 1
If \(F(x) = \int_a^x f(t)dt\), then \(F'(x) = f(x)\).
FTC Part 2
If F is an antiderivative of f, then \(\int_a^b f(x)dx = F(b) - F(a)\).
Understanding Integrals
The definite integral \(\int_a^b f(x)dx\) represents the signed area between the curve f(x) and the x-axis from x=a to x=b.