Question

please give me some toughest sum for polynomial class 9​

Answer 1

If x= root 2 plus 1 then find (x+1/x)^3

Answer 2

Answer:

16√2

Step-by-step explanation:

Given, x=√2 + 1

So,

x+1/x = (√2+1)+ 1/(√2+1)

=(√2+1) + 1(√2-1) / (√2+1)(√2-1)

=(√2+1) + (√2-1) / (√2)² - (1)1

=(√2+1) + (√2 -1) / 2-1

=(√2+1) + (√2-1) / 1

=√2 + 1 + √2 - 1

=2√2

Therefore,

Cubing both the sides,

(x+1/x)³= (2√2)³

(x+1/x)³= 2³* √2³

=8*√2²*√2

=16*√2

=16√2