2.2 Derivatives Great Sand Dunes National Monument, Colorado Greg Kelly, Hanford High School, Richland, WashingtonPhoto by Vickie Kelly, 2003
is called the derivative of at. We write: “The derivative of f with respect to x is …” There are many ways to write the derivative of
“f prime x”or “the derivative of f with respect to x” “y prime” “dee why dee ecks” or “the derivative of y with respect to x” “dee eff dee ecks” or “the derivative of f with respect to x” or “the derivative of f of x”
dx does not mean d times x ! dy does not mean d times y ! does not mean times !
does not mean ! (except when it is convenient to think of it as division.) does not mean ! (except when it is convenient to think of it as division.)
The derivative is the slope function of the original function. The derivative is defined at the end points of a function on a closed interval. Given
GIVEN Find a formula for y’
Find the equation of the line tangent to at x = 4
A function is differentiable if it has a derivative everywhere in its domain. It must be continuous and smooth. Functions on closed intervals must have one-sided derivatives defined at the end points.
To be differentiable, a function must be continuous and smooth. Derivatives will fail to exist at: cornercusp vertical tangent discontinuity
Most of the functions we study in calculus will be differentiable.