given the function
[tex]f(x)=x^2[/tex]right 1
[tex]f(x-1)=(x-1)^2[/tex]reflect accros x axis
[tex]-f(x-1)=-(x-1)^2[/tex]vertical shrink by 1/3
since it says a shrink
vertical compressions a<1
[tex]-\frac{1}{3}f(x-1)=-\frac{1}{3}(x-1)^2[/tex]then the equation is
[tex]-\frac{1}{3}\left(x-1\right)^{2}[/tex]