Glossary
Chain Rule
A rule used to differentiate composite functions, stating that the derivative of $f(g(x))$ is $f'(g(x)) \cdot g'(x)$.
Example:
To find the derivative of , you'd apply the Chain Rule to get .
Constant Multiple Rule
A differentiation rule stating that the derivative of a constant times a function is the constant times the derivative of the function.
Example:
If , then , applying the Constant Multiple Rule.
Derivative of cos x
The rate of change of the cosine function, which is the negative of the sine function.
Example:
When modeling the oscillation of a spring with , the velocity of the spring is , found by taking the Derivative of cos x.
Derivative of e^x
The rate of change of the natural exponential function, which is unique in that it is equal to itself.
Example:
If a population grows exponentially according to , then the rate of population growth, , is also , demonstrating the special property of the Derivative of e^x.
Derivative of ln x
The rate of change of the natural logarithm function, which is the reciprocal of x.
Example:
To find the rate at which a quantity modeled by changes, you'd calculate , using the rule for the Derivative of ln x.
Derivative of sin x
The rate of change of the sine function, which is the cosine function.
Example:
If a particle's position is given by , its velocity is , meaning its instantaneous rate of change of position is the Derivative of sin x.
Power Rule
A fundamental differentiation rule used to find the derivative of functions in the form $x^n$, where the derivative is $nx^{n-1}$.
Example:
To find the rate of change of the volume of a sphere with respect to its radius, , you'd use the Power Rule to get .
Product Rule
A rule for differentiating the product of two functions, given by $(uv)' = u'v + uv'$.
Example:
If you need to find the derivative of , you would use the Product Rule to get .
Quotient Rule
A rule for differentiating the quotient of two functions, given by $(\frac{u}{v})' = \frac{u'v - uv'}{v^2}$.
Example:
To differentiate , you'd apply the Quotient Rule to find .
Second Derivative
The derivative of the first derivative of a function, representing the rate of change of the slope of the tangent line or the concavity of the function.
Example:
If is position, is velocity, and is acceleration, which is the Second Derivative of position.
Tangent Line
A straight line that touches a curve at a single point and has the same slope as the curve at that point, representing the instantaneous rate of change.
Example:
To find the equation of the Tangent Line to at , you'd find and , leading to .
Trig Identities
Equations involving trigonometric functions that are true for all values of the variables for which the functions are defined, often used to simplify expressions before differentiation.
Example:
Before differentiating , you could simplify it to using a fundamental Trig Identity, making its derivative .