SOLUTION: what is a reciprocal

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Question 534254: what is a reciprocal
Found 2 solutions by fcabanski, oberobic:
Answer by fcabanski(1391) About Me  (Show Source):
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The reciprocal of x is 1/x. It's the inverse. The number when multiplied by the original number equals 1.


x * 1/x = 1


For a fraction: x/y * y/x (its reciprocal) = 1.


Answer by oberobic(2304) About Me  (Show Source):
You can put this solution on YOUR website!
The reciprocal is a number that, when multiplied by the original number, yields 1.
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In simplest terms, the reciprocal of the number 'x' is 1/x.
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+x+%2A+%281%2Fx%29+=+x%2Fx+=+1+
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The reciprocal of a fraction is the fraction "upside" down.
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Say you have a fraction 'a/b'. The reciprocal is 'b/a'.
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+%28a%2Fb%29%2A%28b%2Fa%29+=+a%2Fb+%2A+b%2Fa+=+ab%2Fab+=+1+
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As you can imagine, reciprocals can be defined for functions, too.
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Let's say you have 'x +1'. The reciprocal is 1/(x+1).
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+%28x%2B1%29+%2A+%281%2F%28x%2B1%29%29+=+%28x%2B1%29%2F%28x%2B1%29+=+1+
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The reciprocal also is defined by exponents.
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Given you have 'x', that is the same as saying you have 'x^1' because any number to the power 1 = itself.
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+4%5E1+=+4+
+65000%5E1+=+65000+
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We also know that any number raised to the 0th power = 1.
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+4%5E0+=+1+
+65000%5E0+=+1+
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When we multiply the same number raised to powers you add the exponents.
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+x%2Ax+=+x%5E2+
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As noted above, x = x^1
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+x%2Ax+=+x%5E1%2Ax%5E1+=+x%5E2+
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In general,
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+x%5Ea+%2A+x%5Eb+=+x%5E%28a%2Bb%29+
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So you probably can guess the reciprocal of 'x^1'.
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+x%5E1+%2A+x%5E%28y%29+=+x%5E0+
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'y' has to = -1
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+x%5E1+%2A+x%5E%28-1%29+=+x%5E0+=+1+
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This definition of the reciprocal also reveals that negative exponents can be shown as fractions.
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+x%5E%28-1%29+=+1%2Fx+
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That's a lot to cover in one answer, but I hope it gives you feel for the definition and usefulness of the reciprocal.
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