Derivatives of the Trigonometric Functions
Formulas of the derivatives of trigonometric functions sin(x), cos(x), tan(x), cot(x), sec(x) and csc(x), in calculus, are presented along with several examples involving products, sums and quotients of trigonometric functions.
Formulae For The Derivatives of Trigonometric Functions
1  Derivative of sin x
The derivative of f(x) = sin x is given by2  Derivative of cos x
The derivative of f(x) = cos x is given by3  Derivative of tan x
The derivative of f(x) = tan x is given by4  Derivative of cot x
The derivative of f(x) = cot x is given by5  Derivative of sec x
The derivative of f(x) = sec x tan x is given by6  Derivative of csc x
The derivative of f(x) = csc xis given byExamples Using the Derivatives of Trigonometric Functions
Example 1
Find the first derivative of f(x) = x sin xSolution to Example 1:

Let g(x) = x and h(x) = sin x, function f may be considered as the product of functions g and h: f(x) = g(x) h(x). Hence we use the product rule, f '(x) = g(x) h '(x) + h(x) g '(x), to differentiate function f as follows
f '(x) = x cos x + sin x * 1 = x cos x + sin x
Example 2
Find the first derivative of f(x) = tan x + sec xSolution to Example 2:

Let g(x) = tan x and h(x) = sec x, function f may be considered as the sum of functions g and h: f(x) = g(x) + h(x). Hence we use the sum rule, f '(x) = g '(x) + h '(x), to differentiate function f as follows
f '(x) = sec ^{ 2} x + sec x tan x = sec x (sec x + tan x)
Example 3
Find the first derivative of f(x) = sin x / [ 1 + cos x ]Solution to Example 3:

Let g(x) = sin x and h(x) = 1 + cos x, function f may be considered as the quotient of functions g and h: f(x) = g(x) / h(x). Hence we use the quotient rule, f '(x) = [ h(x) g '(x)  g(x) h '(x) ] / h(x)^{ 2}, to differentiate function f as follows
g '(x) = cos x
h '(x) =  sin x
f '(x) = [ h(x) g '(x)  g(x) h '(x) ] / h(x)^{ 2}
= [ (1 + cos x)(cos x)  (sin x)( sin x) ] / (1 + cos x)^{ 2}
= [ cos x + cos ^{ 2}x + sin ^{ 2}x ] / (1 + cos x)^{ 2}

Use trigonometric identity cos ^{ 2}x + sin ^{ 2}x = 1 to simplify the above
f '(x) = [ cos x + 1 ] / (1 + cos x)^{ 2} = 1 / [cos x + 1]