Cuanto es la tercera parte de 39​

Use set buikder notation to represent the following set: {, -2, -1, 0}

Arley is building a model of a city map. in one part of the city, three roads form a right triangle, which harley draws as triangle abc, with the following measures: m∠b=90° and m∠a=30°. in his scale model, the hypotenuse of triangle abc, ac¯¯¯¯¯¯¯¯, has a length of 817−−√ cm. what is the value of a (the length of bc¯¯¯¯¯¯¯¯)?

In which direction does the left side of the graph of this function point? a(x) = 3x - x2 + 4x - 2