The Mathematical Symbol "Approximately Equal To or the Image Of (≒)"

The ≒ Symbol in Mathematics: Delving into its Meanings

The mathematical symbol ≒ is versatile and can signify two distinct concepts: "Approximately Equal To" or "the Image Of". Its usage depends on the context. This article will highlight both these interpretations, offering two illustrative examples for each.

1. Approximately Equal To

This interpretation is common when comparing two quantities that are nearly, but not precisely, equal.

  • Example 1: Suppose a calculation for π results in 3.14159. We can express this approximation as \(π ≒ 3.14159\).
  • Example 2: In experimental physics, if a measurement for the gravitational constant \(G\) yields a value of 6.67429 x 10^-11 m^3 kg^-1 s^-2, one might write: \(G ≒ 6.67430 x 10^-11 m^3 kg^-1 s^-2\), rounding it for simplification.

2. The Image Of

In the realm of mathematics, especially in set theory and mappings, the symbol denotes the image of an element under a specific function or transformation.

  • Example 1: Given a function \(f\) and an element \(x\) in its domain, if \(f(x) = y\), it can be represented as \(x ≒ y\).
  • Example 2: In a transformation \(T\) mapping a point \(P\) to a point \(P'\), this relationship can be expressed as \(P ≒ P'\).

In summary, the symbol ≒ is multifaceted, symbolizing different mathematical concepts based on its contextual application. Distinguishing between its meanings is crucial for accurate comprehension and communication.

Mathematical symbol 'Approximately Equal To or the Image Of'

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Codes for the ≒ Symbol

The Symbol
Alt CodeAlt 8786
HTML Code≒
HTML Entity≒
CSS Code\2252
Hex Code≒

How To Insert the ≒ Symbol

(Method 1) Copy and paste the symbol.

The easiest way to get the ≒ symbol is to copy and paste it into your document.

Bear in mind that this is a UTF-8 encoded character. It must be encoded as UTF-8 at all stages (copying, replacing, editing, pasting), otherwise it will render as random characters or the dreaded �.

(Method 2) Use the "Alt Code."

If you have a keyboard with a numeric pad, you can use this method. Simply hold down the Alt key and type 8786. When you lift the Alt key, the symbol appears. ("Num Lock" must be on.)

(Method 3) Use the HTML Decimal Code (for webpages).

HTML TextOutput
<b>My symbol: &#8786;</b>My symbol: ≒

(Method 4) Use the HTML Entity Code (for webpages).

HTML TextOutput
<b>My symbol: &efDot;</b>My symbol: ≒

(Method 5) Use the CSS Code (for webpages).

CSS and HTML TextOutput
span:after {
content: "\2252";}
<span>My symbol:</span>
My symbol: ≒

(Method 6) Use the HTML Hex Code (for webpages and HTML canvas).

HTML TextOutput
<b>My symbol: &#x2252;</b>My symbol: ≒
On the assumption that you already have your canvas and the context set up, use the Hex code in the format 0x2252 to place the ≒ symbol on your canvas. For example:
JavaScript Text
const x = "0x"+"E9"
ctx.fillText(String.fromCodePoint(x), 5, 5);

(Method 7) Use the Unicode (for various, e.g. Microsoft Office, JavaScript, Perl).

The Unicode for ≒ is U+2252. The important part is the hexadecimal number after the U+, which is used in various formats. For example, in Microsoft Office applications (e.g. Word, PowerPoint), do the following:
[Hold down Alt]
[Press x]

(The 2252 turns into ≒. Note that you can omit any leading zeros.)
In JavaScript, the syntax is \uXXXX. So, our example would be \u2252. (Note that the format is 4 hexadecimal characters.)
JavaScript TextOutput
let str = "\u2252"
document.write("My symbol: " + str)
My symbol: ≒