# Binomial Theorem Approximations/Examples/Arbitrary Example 1

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## Example of Binomial Theorem Approximation

$\paren {1 \cdotp 0 6}^{1/3} \approx 1 \cdotp 019613$

to $6$ decimal places.

## Proof

 $\ds \paren {1 \cdotp 0 6}^{1/3}$ $=$ $\ds \paren {1 + 0 \cdotp 06}^{1/3}$ $\ds$ $\approx$ $\ds 1 + \dfrac 1 3 \paren {0 \cdotp 06} + \dfrac {\paren {\frac 1 3} \paren {-\frac 2 3} } {2!} \paren {0 \cdotp 06}^2 + \dfrac {\paren {\frac 1 3} \paren {-\frac 2 3} \paren {-\frac 5 3} } {3!} \paren {0 \cdotp 06}^3 + \dfrac {\paren {\frac 1 3} \paren {-\frac 2 3} \paren {-\frac 5 3} \paren {-\frac 7 3} } {4!} \paren {0 \cdotp 06}^4$ $\ds$ $\approx$ $\ds 1 + 0 \cdotp 02 - 0 \cdotp 0004 + 0 \cdotp 000133 - 0 \cdotp 00000053$ $\ds$ $=$ $\ds 1 \cdotp 0196128$ $\ds$ $\approx$ $\ds 1 \cdotp 019613$

$\blacksquare$