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Trigonometric valuesTrigonometryHigh schoolabout 0:37

Evaluate cos(180°): animated lesson

A narrated, step-by-step trigonometric values video lesson with captions. Final answer: -1.

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Video with a synthetic English voice and captions. Pick another language for subtitles in that language, or open the interactive version.

Video narrated by a synthetic voice (Piper TTS, en_US-ljspeech-high voice (LJ Speech dataset, public domain)); the steps come from our maths engine and the answer was checked independently. Download MP4 (0.2 MB) · Captions (WebVTT)

Steps on screen

1. The problem
Worked example
$\cos\left(\frac{180\cdot\pi}{180}\right)$
2. Step by step
1. $\cos\left(\frac{180\cdot\pi}{180}\right)$
  Read the expression
2. $\cos\left(\frac{180\cdot\pi}{180}\right) = \cos\left(\pi\right)$
  Simplify exactly
3. $\cos\left(\frac{180\cdot\pi}{180}\right) = -1$
  Evaluate using the order of operations (parentheses, exponents, multiplication and division, addition and subtraction)
3. The answer
$-1$
cos((180*pi/180)) = -1
4. Check
- Decimal value: -1

Transcript

The problem. Here is the problem: cos((180 times pi/180)). Evaluate a numerical expression.

Step by step. Read the expression. Simplify exactly. Evaluate using the order of operations (parentheses, exponents, multiplication and division, addition and subtraction).

The answer. So the answer is negative 1. Operations are applied in the standard order: parentheses, exponents, multiplication and division from left to right, then addition and subtraction from left to right.

Check. Decimal value: negative 1.

About trigonometric values

Exact values of sine, cosine, tangent and their reciprocals and inverses.

Evaluate cos(180°): Trigonometric values Step-by-Step Lesson