Question

problema matrici! ajutorrrrrr

Answer 1

Răspuns:

a) $I_2=\begin{pmatrix}1 & 0\\0 & 1\end{pmatrix}$

Rezultă

$2^{x-1}=1\Rightarrow x-1=0\Rightarrow x=1$

$\log_2(a-1)=0\Rightarrow a-1=1\Rightarrow a=2$

$4y^2-3x=1\Rightarrow 4y^2-3=1\Rightarrow y^2=1\Rightarrow y=\pm 1$

b) $O_2=\begin{pmatrix}0 & 0\\0 & 0\end{pmatrix}$

Rezultă

$3^x-9^x=0\Rightarrow 3^x(1-3^x)=0\Rightarrow 3^x=1\Rightarrow x=0$

$\lg\dfrac{y^2-2y}{3}=0\Rightarrow\dfrac{y^2-2y}{3}=1\Rightarrow y^2-2y-3=0\Rightarrow y_1=-1, \ y_2=3$

$a+3bi-1=0\Rightarrow\begin{cases}a-1=0\\3b=0\end{cases}\Rightarrow\begin{cases}a=1\\b=0\end{cases}$

$3!-C_n^2=0\Rightarrow 6-\dfrac{n(n-1)}{2}=0\Rightarrow n^2-n-12=0\Rightarrow n=4$

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