Question

Determinati solutiile reale pentru: 3 la puterea x²= 81

Answer 1

   
[tex]3^{x^2} =81 \\ \\ 3^{x^2} =3^4 \\ \\ x^2 = 4 \\ \\ x^2-4 = 0 \\ \\ (x-2)(x+2)=0\\ \\ x-2 = 0~~\Longrightarrow~~\boxed{x_1 = 2} \\ \\ x+2 = 0~~\Longrightarrow~~\boxed{x_2 = -2} [/tex]