SOLUTION: evaluate without using a calculator, using binomial theorem, 1) 4th root (624) 2) 1/(1+x)^1/2

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Question 825831: evaluate without using a calculator, using binomial theorem,
1) 4th root (624)
2) 1/(1+x)^1/2

Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
1) I am not sure exactly what you are expected to do to evaluate root%284%2C624%29 without using a calculator, using binomial theorem, but this is what I would do.
4%5E4=256 and 5%5E4=625
Since 624 is so close to 625, i would expect root%284%2C624%29 to be very close to 5, so let's try 4.9.

Since 624 is much closer to 625 than to 576.48, I would expect root%284%2C624%29 to be much closer to 5 than to 4.9, so I would try 4.99.

= about625-5%2B0.015=620.015
At this point, knowing that 4.99%5E4=about620.015 and 5.00%5E4=625.000, I would estimate root%284%2C624%29=4.998 by assuming that f%28x%29=root%284%2Cx%29 is approximately linear between 4.990 and 5.000.

2) There is nothing that can be evaluated in
1%2F%281%2Bx%29%5E1%2F2=1%2Fsqrt%281%2Bx%29 , since we do not have a value for x .
That expression can be rationalized as