# What does “-2E-07x” means? [duplicate]

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I'm a programmer who had always been lacking some mathematical skills, yes it's a shame, I know.

I'm making this little software for a biologist friend, and at some point I need to pull out a graph out of a formulas he gave me.

Problem is, I don't understand it, and before asking him if there are no mistake in it (and possibly look like a fool), i thought I'd ask the community :)

So here is the formula :

y = -2E-07x6 + 1E-05x5 - 0.0002x4 + 0.0015x3 - 0.0052x2 + 0.0063x - 0.0007

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## marked as duplicate by J. M., The Chaz 2.0, Amzoti, rschwieb, SashaMay 8 '13 at 16:43

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nEm is normally shorthand for $n10^m$ so -2E-07x6 is probably short hand for $(-2)10^{-7}x^6$. – Dan Rust May 8 '13 at 15:43
guessing E means "exponent". also guessing the reason it's capitalized is because it fits conveniently into LCD displays on calculators – amr May 8 '13 at 16:57

## 2 Answers

A polynomial with x to the given power? So the term 0.0052x2 might be interpreted as 0.00052*x^2, i.e., the number 0.0052 times the variable x to the second power. Similarly, 2E-07x6 might be 2*10^(-7) x^6, so the coefficient of the 6th power of x is 2*10^(-7).

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Just guessing: $$y = -2\cdot 10^{-7}\cdot x^6 + 10^{-5}\cdot x^5 - 2\cdot 10^{-4}\cdot x^4 + 1.5 \cdot 10^{-3}\cdot x^3 - 5.2\cdot 10^{-3}\cdot x^2 + 6.3\cdot 10^{-3}\cdot x - 4\cdot 10^{-4}$$ which is a simple polynom of degree 6.

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