Use Implicit Differentiation to Determine the Slope of the Graph $x ^ { 1 / 2 } + y ^ { 1 / 2 } = 4 \text { at } ( 1,9 )$

Short Answer

Use implicit differentiation to determine the slope of the graph of $x ^ { 1 / 2 } + y ^ { 1 / 2 } = 4 \text { at } ( 1,9 )$ Enter just an integer.