Cotangent of an angle in radians calculator
This cotangent of an angle in radians calculator evaluates cosine and sine for the supplied radian measure, then divides cosine by sine.
Run — free
It is designed for calculations that already use radians, so no degree conversion or unit selector is needed. The result includes the intermediate sine and cosine values, the formula, and configurable rounding. Because division by zero has no finite result, every whole multiple of pi is reported as undefined instead of returning a misleading extremely large floating-point number.
Enter the angle as a radian measure
Provide a finite real number in the angle field. The number is interpreted directly as radians: for example, about 0.785398 represents one quarter of pi, while about 1.570796 represents one half of pi. Do not enter a degree value unless you convert it first, because 45 is treated as 45 radians rather than 45 degrees. Decimal notation and scientific notation are accepted by the computational core, and the published input range prevents values so enormous that floating-point argument reduction would make the result unhelpful. You may also choose a precision from zero through fifteen decimal places. Precision controls the displayed numeric fields, not the internal sine, cosine, or division, so rounding occurs only after the cotangent has been calculated. The response repeats the normalized angle, identifies the unit as radians, and supplies sine and cosine beside cotangent. Those intermediate values make it straightforward to audit the result or reuse the calculation in a lesson, worksheet, or software test.
Understand the cosine-over-sine calculation
Cotangent is defined here by the identity cot(θ) = cos(θ) / sin(θ). The solver evaluates both standard JavaScript trigonometric functions at the radian angle and performs that quotient without converting units. This definition also explains the sign of the result. In the first and third quadrants, cosine and sine have the same sign, so cotangent is positive. In the second and fourth quadrants they have opposite signs, so cotangent is negative. At odd half multiples of pi, cosine is zero while sine is nonzero, making cotangent exactly zero in mathematical terms; the rounded response removes negative zero so JSON consumers receive an ordinary zero. The period is pi, meaning that adding or subtracting any whole multiple of pi produces the same cotangent wherever the function is defined. The included sine and cosine fields help distinguish a small valid answer near a half multiple of pi from an undefined answer at a whole multiple of pi.
Recognize undefined angles and numerical boundaries
Cotangent is undefined whenever sine is zero. In radians, that occurs at every integer multiple of pi: zero, pi, negative pi, two pi, and so on. A floating-point machine cannot store pi exactly, so the solver detects whether the angle divided by the platform value of pi is within a tight tolerance of an integer. This correctly recognizes ordinary programmatic inputs such as Math.PI and 2 * Math.PI while avoiding a fabricated giant answer caused only by the tiny residual returned by a sine implementation. An undefined case is returned through the standard invalid-input error channel with a clear message. Angles that are merely close to a multiple may have a very large but valid cotangent, reflecting the function’s vertical asymptote. For reproducible automation, send enough digits to represent your intended radian value and retain a suitable output precision. The calculation is deterministic, uses no network service, stores no input, and performs the same fixed sequence of validation, trigonometric evaluation, division, and rounding on every request.
What you can do with it
Check trigonometry homework
Verify a cotangent result while seeing the cosine and sine values used in the quotient.
Validate radian-based software
Generate deterministic expected cotangent values for unit tests that already express angles in radians.
Analyze periodic models
Evaluate cotangent in wave, rotation, or geometry calculations and identify its undefined multiples of pi.
FAQ
What formula does the calculator use?
It uses cot(θ) = cos(θ) / sin(θ), with θ interpreted in radians.
Why is cotangent undefined at multiples of pi?
Sine equals zero at every whole multiple of pi, and division by zero is undefined.
Can I enter degrees?
No. This capability treats every angle as radians, so convert degrees to radians before submitting the value.
What does precision change?
It sets the number of decimal places in numeric output fields from zero through fifteen; calculation happens before rounding.
How much does an API request cost?
Each API request costs $0.002. The browser calculation can use the same deterministic core.
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/trig/cot-radians \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"angle":0.7853981633974483}'const res = await fetch("https://api.kit.forhosting.com/trig/cot-radians", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"angle": 0.7853981633974483
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/trig/cot-radians",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"angle": 0.7853981633974483
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/trig/cot-radians", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"angle":0.7853981633974483}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"angle":0.7853981633974483}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/trig/cot-radians", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"angle": 0.7853981633974483
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "trig.cot_radians",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |