Question

Making use of the cube root table, find the cube root of the following (currect to three decimal places):

(ii) 700

(ii) 7000

Answer 1

(i) 700

Given, 

700 = 70×10 By using cube root table 700 will be in the column \(\sqrt[3]{10x}\) against 70.

So we have,

\(\sqrt[3]{700} = 8.879\)

(ii) 7000

7000 = 70×100

∴ \(\sqrt[3]{7000} = \sqrt[3]{7\times1000}\) = \(\sqrt[3]{7}\times\sqrt[3]{1000}\)

By using cube root table,

We get,

\(\sqrt[3]{7} = 1.913 \)  and  = \(\sqrt[3]{1000} = 10\)

∴ \(\sqrt[3]{7000}\) = \(\sqrt[3]{7}\times\sqrt[3]{1000}\) = \(1.913\times10 = 19.13\)