BELIEVE   ME   NOT!    - -     A   SKEPTIC's   GUIDE  

... times.¹

Since our dollar will be worth less a year from now, we should really call it deflation!

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... change:²

The error introduced by this approximation is not very serious.

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... time.³

Banks, insurance companies, trade unions, and governments all pretend that they don't assume this, but they would all go bankrupt if they didn't assume it.

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... time.⁴

A politician trying to obfuscate the issue might say, "The rate of decrease is decreasing."

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... combination⁵

"Linear combination" means we multiply each term by a simple constant and add them up.

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... derivatives,⁶

The CHAIN RULE for derivatives says that if  z  is an explicit function of  y,  z(y),  and  y  is an explicit function of  x,  y(x),  then  z  is an implicit function of  x  and its derivative with respect to  x  is given by

$${dz \over dx} = {dz \over dy} \cdot {dy \over dx}.$$

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... us.⁷

This is exactly what a "scientific" hand calculator does when you push the function key whose name will be revealed momentarily.

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... either⁸

Now you know which key it is on a calculator.

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... shown⁹

Watch for this phrase! Whenever someone says "It can easily be shown...," they mean, "This is possible to prove, but I haven't got time; besides, I might want to assign it as homework."

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