[tex]f(x) = \sqrt{3x} + 7 \\ \\ f ^{ - 1} (x) = ( \sqrt{3x} + 7) ^{ - 1} \\ \\ f ^{ - 1} (x) = \frac{1}{ \sqrt{3x} + 7} \\ \\ \\ f ^{ - 1} (2) = \frac{1}{ \sqrt{3(2)} + 7} \\ \\f ^{ - 1} (2) = \frac{1}{ \sqrt{6} + 7} \\ \\ f ^{ - 1} (2) = \frac{1}{ \sqrt{6} + 7} \times \frac{ \sqrt{6} - 7 }{ \sqrt{6} - 7 } \\ \\ f ^{ - 1} (2) = \frac{ \sqrt{6} - 7 }{(6 - 49)} = \frac{ \sqrt{6} - 7 }{ - 43} \\ \\ f ^{ - 1} (2) = \frac{ \sqrt{6} - 7 }{ - 43} = \frac{2.449 - 7}{ - 43} \\ \\ f ^{ - 1} (2) = \frac{ - 4.551}{ - 43} \\ \\ f ^{ - 1} (2) = \frac{ 4.551}{ 43} =0.10584[/tex]
I hope I helped you^_^
