Answer:
[tex]\large \boxed{\sf \ \ \dfrac{x^2}{x^4+1}=\dfrac{1}{7} \ \ }[/tex]
Step-by-step explanation:
Hello,
We know that (let's assume that x is different from 0 as we cannot divide by 0)
[tex]x+\dfrac{1}{x}=3[/tex]
and we want to estimate
[tex]\dfrac{x^2}{x^4+1}[/tex]
Let's take the square.
[tex]9=3^2=(x+\dfrac{1}{x})^2=x^2+2\cdot x \cdot \dfrac{1}{x}+\dfrac{1}{x^2}=x^2+2+\dfrac{1}{x^2}=\dfrac{x^4+1}{x^2}+2[/tex]
So, we can write
[tex]\dfrac{x^4+1}{x^2}=9-2=7 \\ \\\\\text{*** let's take the inverse ***} \\ \\\dfrac{x^2}{x^4+1}=\dfrac{1}{7}[/tex]
Hope this helps.
Do not hesitate if you need further explanation.
Thank you