Question

Dada a função f(x) = 2x + 1, e seja f-1 sua função inversa, o valor de f- -1 (7) é: * 1 ponto
4
2
0
3
1​

Answer 1

$\large\boxed{\begin{array}{l}\sf f(x)=2x+1\\\sf 2x=f(x)-1\\\sf x=\dfrac{f(x)-1}{2}\\\\\sf f^{-1}(x)=\dfrac{x-1}{2}\\\\\sf f^{-1}(7)=\dfrac{7-1}{2}\\\\\sf f^{-1}(7)=\dfrac{6}{2}\\\\\sf f^{-1}(7)=3\end{array}}$