Question

find the value of X​

Answer 1

Answer:

Step-by-step explanation:

Answer 2

we have given, $x=c\sqrt{b}+4$ and we have to find x + 1/x.

this question is based on rationalisation. let's see how ?

$\frac{1}{x}=\frac{1}{c\sqrt{b}+4}$

using rationalisation concept,

$\frac{1}{x}=\frac{c\sqrt{b}-4}{(c\sqrt{b}+4)(c\sqrt{b}-4)}$

$\frac{1}{x}=\frac{c\sqrt{b}-4}{bc^2-16}$

now, x + 1/x = $c\sqrt{b}+4+\frac{c\sqrt{b}-4}{bc^2-16}$

= $\frac{(c\sqrt{b}+4)(bc^2-16)+c\sqrt{b}-4}{bc^2-16}$

= $\frac{c^3b\sqrt{b}-15c\sqrt{b}+4bc^2-68}{bc^2-16}$

hence, x + 1/x = $\frac{c^3b\sqrt{b}-15c\sqrt{b}+4bc^2-68}{bc^2-16}$