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Hello I came across a math equation and I was wondering what did the "e" stand for? the equation is : y=47931x-1E+0.8 Can someone please help me by showing what the E stands for and the answer for my equation. I know that I need to sub in a point for x so the only thing stopping me from answering the question is what to do for the 1E+0.8 part.

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    It is scientific notation, the e or E stands for $10^x$ where x is the number following the e/E – 2017-02-11
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    Are you sure it is $E+0.8$? That decimal point seems unlikely. – 2017-02-11
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    Can you write down *exactly* what the expression said. Is "x" the letter $x$ or the times symbol $\times$. I s the E capitolized or not. And what *was* the equation? Was this a math book? A chemistry book? What was the equation supposed to *mean*? And were any of the terms "rised" ? $1E$ vs $1^E$ or ... whatever. – 2017-02-11
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    Why was this question upvoted? The tags are all wrong! We do not know whether $x$ in the equation is a variable or just the times symbol. The question is not clear! – 2017-02-11

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If it's a capital E, it should be scientific notation, specifically E notation.

Because 100,000,000 takes up a lot of space and can be difficult to compare with other numbers, it's written as $1$x$10^8$. Some calculators (and some books, to match) write this with an E:

Avogadro's constant in E notation By PRHaney - Own work, CC BY-SA 3.0

But that's done with integers, and you have $0.8$, so it must be

$$y = 47931x - e^{0.8},$$

using the natural exponential function.

Note that you can use lowercase e for scientific notation, but capital E should not be used for the natural exponential function.

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    Note that it's not unheard of to use a lower-case `e` for scientific notation. For instance, in many programming languages, when formatting output of numbers, the are presets for both conventions. – 2017-02-11
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    [+1] Nice piece of art. We could call it E-art... – 2017-02-11
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    @Arthur Thanks! I added that in. – 2017-02-12
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E = Exponentiation in base $10$.

Examples:

$$1.23\ \text{E+0.2} = 1.23\cdot 10^{0.2}$$

$$1.23\ \text{E-2.1} = 1.23\cdot 10^{-2.1}$$

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    But you you must admit the use of a decimal, while not theoretically impossible is highly unusual. The usual *point* of scientific notation is to shift decimal points so it is usually always done iwht positive or negative integers. – 2017-02-11
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    Yes, indeed is quite strange. I just gave a generalisation of the meaning, but I wouldn't ever expect a non integer exponential! – 2017-02-11
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    This is probably the correct interpretation (I'm having a hard time thinking of any other) but I think we need to clarify where the OP read the expression and was it actually written as such. Hypothetically $y = 47931x - 1E+0.8$ *could* mean $y = 47931x - 10^{0.8} = 47931x - \sqrt[5]{10,000}$ but that would be .... weird. – 2017-02-11