Math Is Fun Forum

Sorry,I'm trying to write you the answer but it doesn't work

But you can try values from 0.000000001  to  9.99999,or to do this:

There are many ways to evaluate this kind of calcul:
1.First   multiply 4X8,than 4X6,4X6 and 4X2
and then get one column under the numbers you wrote,and start again with the 6 but just one place into the left.
And then just do the sum of the two columns
2.Here is another example
If you want to evaluate this calcul do like this:
2668X100=266800
2668X10=26680 now 26680X3=80040
2668X3X2=8004X2=16008

and than do the substraction of all the results you had,do like this: 266800-80040-16008=170752 and this is the result of multiplying 2668 by 64!!!!!!!
Do you understand how to do it????

Here is the solution about the BC=x/2^(1/2)

From B make a line down from b to the segment CF,and the point that touch CF name it A.
CF=DE=x so CA=1/2*x

From C make a vertical line,and from B a horizontal line,and the point that begins to both of segments name it H,and you 'll have a square (HBCA).
Now:
CA=BA=x/2
BC^2=CA^2+BA^2
BC^2=x^2/4+x^2/4
BC^2=2x^2/4
BC^2=x^2/2
BC=squarerrot(x^2/2)
BC=x/squareroot(2)