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If you use Windows calculator in scientific mode you may notice the lack of a
square root button. I think that here Microsoft assumed that somebody using the
scientific calculator would know how to do a square root themselves without a button
for it. However, for anyone who doesn't know how to do it, here it is:
To find the square root of 9 you can raise 9 to the power of the reciprocal of 2
(or 1/2, which is 0.5): 90.5 = 3
In the same way you could find the cube root of 27: 271/3 = 270.3
(recurring) = 2.9 (recurring)
Explanation:
It's obvious that the square root of a number multiplied by itself will equal
the number, so the square root of 9 is 3, 3*3 is 9.
If 90.5 is 3 and 3*3 is 9, then 90.5 * 90.5
is also 9.
We know from the rules of indices that when multiplying, one must add the
indexes (and if the bases are the same then they are not multiplied). Now, consider what happens when fractions are added:
1 1
--- + --- = 1
2 2
Since 0.5 is the same as 1/2, 90.5 * 90.5 can be simplified to 91, or 9
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Square root on Windows calculator