[tex]\text{Given that,}~ f(x) = 3x+5~ \text{and}~ g(x)=\sqrt{x^2 +3}\\\\(g \circ f)(-1)\\\\=g(f(-1))\\\\=g(3(-1) +5)\\\\=g(-3+5)\\\\=g(2)\\\\=\sqrt{2^2+3}\\\\=\sqrt{4+3}\\\\=\sqrt{7}[/tex]