Cześć!
[tex](\frac{2}{3})^{x^2} > (\sqrt{\frac{3}{2}})^x \iff (\frac{2}{3})^{x^2} > (\frac{3}{2})^{\frac{1}{2} \cdot x} \iff (\frac{2}{3})^{x^2} > (\frac{2}{3})^{-\frac{1}{2}x} \iff\\\\\iff x^2<-\frac{1}{2}x \iff x^2+\frac{1}{2}x<0 \iff 2x^2+x<0 \iff x(2x+1)<0 \iff\\\\\iff x \in (-\frac{1}{2}; 0)[/tex]
Pozdrawiam!