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Section 3: Functions 44
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From a program, you use the ABS function which changes the sign, if negative. For example,
calculate the absolute value of 3 and –3.
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Press
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See Displayed
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Comment
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3 gABS
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|+3|
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CHS
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gABS
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|–3|
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Functions of x and the Exponential Function (yx)
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These functions are listed in Figure 33. They all leave the result in the X-register.
All expect an input value to be in the X-register. yX expects, in addition, a
y value in the Y-register. It is worth noting that the conditions given
for INPUT VALUE(S) can generally be predicted by common sense. For example, the table tells us
that to calculate the reciprocal, the input value cannot be 0, which is exactly what we would expect
because we ordinarily attach no meaning to 1 ÷ 0. If we attempt to calculate the reciprocal of
zero, the blinking display emphatically warns us of the error. Try it. Just press CLx g1/x.
You can stop the blinking by pressing any key.
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Sample Case: Common Logarithm. Calculate the power gain in decibels of an amplifier yielding
twice the value of the input power.
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Note: decibels = 10 log (2)
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Press
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See Displayed
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Comment
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10 ENTER
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Save value 10.
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2 fLOG
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Log 2.
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×
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Answer.
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