Quantities x, y, z and t satisfy z=f(x,y) , x=g(t) and y=h(t) .

Knowing that g(3)=1 , g(3)=1 , h(3)=2 , h(3)=0 , fx(1,2)=1 , fy(1,2)=3 , calculate dz/dt when t=3

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