Question

determine: a) O dominio de f(x)=2/x-5 b) A inversa de f(x)=2x+1

Answer 1

a) D(f) = {x∈ IR/ x ≠ 0 }
b) f:IR → IR , f(x) = 2x + 1
x = 2y + 1 => 2y = x - 1 => y = (x - 1)/2
f⁻(x) : IR → IR, f⁻¹(x) = (x - 1) /2

D(f⁻¹(x)) = IR

Answer 2

a)  f(x) =   2
              x - 5

x - 5 ≠ 0 ==> x ≠ 5

D = R - { 5 }
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b) f(x) = 2x + 1

D = R