Derivative of cot(x)
Answer
Derivative of cot(x)
- Rule Used
- Trigonometric Rule
- Steps
- Recognize the trigonometric function . These six derivatives are standard; a cofunction (cos, cot, csc) picks up a minus sign.
- Apply the standard derivative: = -*.
- Final answer: -*
d/dx cot(x) = -csc(x)^2. The derivative exists on the same open intervals as the function, and it blows up at the vertical asymptotes.
Instant step-by-step solution for cot(x)
Derivative of cot(x) = -sec(x)^2*tan(x)^(-2) Solve step-by-step for free: https://derivativecalculatorai.com/derivative-of-cot-x
Derivative
cot(x) → -csc(x)^2engine: -sec(x)^2*tan(x)^(-2)
Graph of the function and its derivative
The solid curve is f. The dashed curve is f′. Vertical gaps are asymptotes or jumps, not extra zeros.
Why the derivative has this form
Cotangent is cos/sin, the cofunction of tangent. The quotient rule produces a numerator −sin^2 − cos^2 = −1, over sin^2, which is −csc^2(x). Every term in the numerator is negative, so there is no cancellation into a plus the way tangent's numerator became +1. Queries for the derivative of cot land on this sign.
Apply the trigonometric derivative to cot(x). The form to remember, already simplified, is -csc(x)^2.
The derivative exists on the same open intervals as the function, and it blows up at the vertical asymptotes.
At x = 1, substitute into the simplified form -csc(x)^2. That number is the slope of cot(x) there; a secant over a small step in x lands next to it.
Worked derivative
- Write f(x) = cot(x).
- Apply the trigonometric derivative to cot(x). The form to remember, already simplified, is -csc(x)^2.
- At x = 1, substitute into the simplified form -csc(x)^2. That number is the slope of cot(x) there; a secant over a small step in x lands next to it.
Common mistakes
Answering csc(x)^2
csc^2(x) without the minus is the derivative of −cot, or the pattern of sec^2 copied onto the wrong function. Cotangent decreases on (0, π).
Swapping cot(x) with its cofunction
Sine and cosine, tangent and cotangent, secant and cosecant are not interchangeable. The minus sign lives on the cofunction side.
Related rule and examples
- Trigonometric derivatives — The rule page lists this example and the others in the same family.
- Quotient rule — The rule page lists this example and the others in the same family.
- Derivatives of trigonometric functions — Same family of differentiation, different function.
- Derivative of sin(x) — Same family of differentiation, different function.
- Derivative of cos(x) — Same family of differentiation, different function.
- Derivative of tan(x) — Same family of differentiation, different function.
- Derivative of sec(x) — Same family of differentiation, different function.
- Derivative of csc(x) — Same family of differentiation, different function.
Frequently asked questions
What is the derivative of cot(x)?
-csc(x)^2. Cotangent is cos/sin, the cofunction of tangent. The quotient rule produces a numerator −sin^2 − cos^2 = −1, over sin^2, which is −csc^2(x). Every term in the numerator is negative, so there is no cancellation into a plus the way tangent's numerator became +1. Queries for the derivative of cot land on this sign.
Which wrong answer shows up for cot(x)?
csc^2(x) without the minus is the derivative of −cot, or the pattern of sec^2 copied onto the wrong function. Cotangent decreases on (0, π).
Where is the derivative of cot(x) defined?
The derivative exists on the same open intervals as the function, and it blows up at the vertical asymptotes.