Y=-0,8^2

It seems like there might be a small typo in your equation. If you meant to write \( y = -0.8x^2 \), then you have a quadratic equation in terms of \( x \) that opens downwards (since the coefficient of \( x^2 \) is negative). If you intended to write something else or need assistance with a specific aspect of this expression (like graphing it, finding its vertex, or solving for \( x \)), please provide more details!