Answer:
4ˣ + 4⁻ˣ es igual a 7
Step-by-step explanation:
4ˣ + 4⁻ˣ
Dónde;
2ˣ + 2⁻ˣ = 3
Nosotras tenemos
[tex]2^x + \dfrac{1}{2^x} = 3[/tex]
[tex]2^{2\cdot x} +1 = 3 \cdot 2^x[/tex]
[tex]2^{2\cdot x} - 3 \cdot 2^x +1 = 0[/tex]
Deje que 'a' represente 2ˣ, tenemos;
a² - 3·a + 1 = 0
a = (3 ± √(3² - 4 × 1 × 1))/2 = (3 ± √5)/2
∴ a = 2ˣ = (3 ± √5)/2
((3 ± √5)/2)^2 - 3×(3 ± √5)/2 + 1
x = ln(3 ± √5)/2/(ln(2))
4ˣ + 4⁻ˣ = 4^(ln((3 ± √5)/2)/(ln(2))) + 4^(-(ln((3 ± √5)/2)/(ln(2)))) = 7
∴ 4ˣ + 4⁻ˣ = 7.
