Question

The expression $\frac{1}{\sqrt{4x+1}}[{\left[\frac{1+\sqrt{4x+1}}{2}\right]}^7-{\left[\frac{1+\sqrt{4x+1}}{2}\right]}^7]$ is a polynomial in x of degree ?

• A. $0$
• B. $4$
• C. $7$
• D. Not defined

Answer 1

The correct option is D Not defined

let $\sqrt{4x+1}=y$

Now $\frac{1}{y}[[\frac{1+y}{2}{]}^7-[\frac{1+y}{2}{]}^7]$

now let $[\frac{1+y}{2}]=m$

hence $\frac{1}{y}[m^7-m^7]=0$