# Why not try this or is it too difficult?

Calculus Level pending

$$f\left( x \right) =1+\left| x \right| -{ x }^{ 2 }$$

Find $$\frac { d }{ dx } f\left( x \right)$$ when $$f\left( \frac { 1+\sqrt { 5 } }{ 2 } \right) =x$$

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