Question

If you could help that would be so amazing im struggling w this concept :)

Answer 1

`\bf ~\hspace{7em}\textit{negative exponents} \\\\ a^(-n) \implies \cfrac{1}{a^n} ~\hspace{4.5em} a^n\implies \cfrac{1}{a^(-n)} ~\hspace{4.5em} \cfrac{a^n}{a^m}\implies a^na^(-m)\implies a^(n-m) \\\\[-0.35em] \rule{34em}{0.25pt}`

`\bf f(x)=\cfrac{20}{4+3e^(-0.2x)}\implies f(3)=\cfrac{20}{4+3e^{-0.2(\stackrel{\downarrow }{3})}}\implies f(3)=\cfrac{20}{4+3e^(-0.6)} \\\\\\ f(3)=\cfrac{20}{4+3(1)/(e^(0.6))}\implies f(3)=\cfrac{20}{4+3\frac{1}{e^{(3)/(5)}}}\implies f(3)=\cfrac{20}{4+3\frac{1}{\sqrt[5]{e^3}}} \\\\\\ f(3)=\cfrac{20}{4+\frac{3}{\sqrt[5]{e^3}}}\implies f(3)\approx\cfrac{20}{4+5.6464}\implies f(3)\approx 3.5421`

you could also just use plug in 0.6 as the exponent for "e", Euler's constant, in your calculator, and that works the same.