Derivatives of Constant Multiples
Example:
y = 9*sin(sqrt(q) - 10*q)
The first thing to notice when finding the derivative of this function
is that it is
the product of a constant and another function,
as shown in color below:
| y |
= |
9 |
sin(sqrt(q) - 10*q) |
The Derivative Rule for Constant Multiples:
The derivative of a constant multiple is the constant times thederivative of the function.
If
then the derivative of
z is
| |
z' |
= |
( c |
f(x) )' |
| |
|
= |
c |
f '(x) |
So our example,
| y |
= |
9 |
sin(sqrt(q) - 10*q) |
we can think of as
So the derivative is
| y ' |
= ( |
c |
f(q) |
)' |
| |
= |
c |
f '(q) |
|
| |
= |
9 |
(sin(sqrt(q) - 10*q))' |
|
and we just need to know the derivative on the right-hand
side of the equation. In this case this is
| sin(sqrt(q) - 10*q) |
= |
cos(sqrt(q) - 10*q) ((1/2)*q-1/2 - 10) |
(by the chain rule) |
so the finished derivative is
| y ' |
= |
9 |
( cos(sqrt(q) - 10*q) ((1/2)*q-1/2 - 10) ) |
| |
= |
9*cos(sqrt(q) - 10*q) ((1/2)*q-1/2 - 10) |
![[]](/images/boxby.gif)
additional explanation for the derivative of constant multiples
see another derivative of constant multiples example
practice gateway test
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Page Generated: Mon Jan 19 00:02:54 2026
Comments to Gavin LaRose
glarose@umich.edu
©2001 Gavin LaRose,
University of Michigan Math Dept.