Answer:
after working for at least 10 1/4 years
Step-by-step explanation:
After working for at least 10 1/4 years a project manager would be eligible for a $20,000 monthly salary.
A quadratic equation, [tex]ax^{2} +bx+c=0[/tex] is solved by
[tex]x=\frac{-b \pm \sqrt{b^2-4ac} }{2}[/tex]
Given function [tex]f(x)=x^4-10x^2+10000[/tex]
Function that has monthly salary $20,000 will be [tex]x^4-10x^2+10000=20000[/tex]
[tex]x^4-10x^2+10000-20000=0[/tex]
[tex]x^4-10x^2-10000=0[/tex]
Now using the formula [tex]x=\frac{-b \pm \sqrt{b^2-4ac} }{2}[/tex]
[tex]x^2=\frac{10 \pm \sqrt{10^2+40000} }{2}[/tex]
[tex]x^2=\frac{10 \pm \sqrt{40100} }{2}[/tex]
[tex]x^2=\frac{10 \pm 200.2}{2}[/tex]
[tex]x^2=5 \pm 100.1[/tex]
[tex]x^2=105.1[/tex]
[tex]x=\sqrt{105.1}[/tex]
[tex]x=10.25[/tex]
Hence, after working for at least 10 1/4 years a project manager would be eligible for a $20,000 monthly salary.
Learn more about quadratic equation here:
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