1. Let $\tan x, \tan \left(\frac{\pi}{4}-x\right)$ be the roots of the equation
$$
a x^{2}+b x+c=0
$$

Then the graph of the function $y=a x^{2}+b x-c$ must pass through the point with coordinates $\qquad$ .
$$
\text{-1. }(1,0)
$$

From the problem, we know that $a+b=c$.
Therefore, the graph of the function must pass through the point $(1,0)$.