Anurag Kishore
Last Activity: 14 Years ago
Hi
As we know that 21/2 is irrational so its value is non recurring and is equal to 1.414213562..........
But if you want value by differential approximation proceed as follows
Let,
f(x) = x1/2
=> f/(x) = 1/2 (x-1/2)
Let x = 4 and $x = -2
Now by differential approximation
f(x+$x) - f(x) = f/(x) . $x
=> f(4 - 2) - f(4) = 1/2(4-1/2) . (-2)
=> f(2) - f(4) = -1/2
but from above f(x) = x1/2
=> 21/2 - 41/2 = -1/2
=> 21/2 = 2 - 1/2 =3/2 =1.5
Note differential give only approximate value and not exact
Thanks