How do you use linear approximation to estimate root3( 64.1)364.1?

1 Answer
Jul 20, 2016

root(3)64.1=4.002083364.1=4.002083.

Explanation:

For a fun. f, f(x+h)~=f(x)+hf'(x).................(1).

Consider the fun. f(x)=root(3)x=x^(1/3) rArr f'(x)=1/3*x^(-2/3)

We take x=64, and, h=0.1 in (1). Therefore,

f(64+0.1)~=f(64)+0.1f'(64)

:.(64.1)^(1/3)~=64^(1/3)+0.1*1/3*64^(-2/3)=4+0.1*1/3*4^(-2)

=4+1/10*1/3*1/16=4+1/480~=4+0.002083=4.002083.

Thus, root(3)64.1=4.002083.