COME FARE GRAFICI CON WolframAlpha (vedi QUI)
HOW TO MAKE GRAPHS WITH WolframAlpha (see HERE)

plot -3*x + 1
plot -3*x + 1, -2 < x < 3
plot -3*x + 1, 0 < y < 3
plot 3/(1-x), -2 < x < 3
plot {3/(1-x), 2/x}, -2 < x < 3
plot {3/(1-x), 2/x}, -2 < x < 3, -5 < y < 8
plot a*x^2 + b*x + c if a = 1, b = -2, c = 3
plot a*x^2 + b*x + c if a = 1, b = -2, c = 3, -1 < y < 10
plot y = x^2+x+a for a = -1, 0, 1, 2, 3, -3 < x < 2, -2 < y < 7
circle(center=(1,0), radius=1), line (0,0),(1,1)
polygon (-1,1),(2,1),(2,2),(-1,2); polygon (0,0), (2,0),(1,2)
polygon (5,15),(15,5),(50,5),(70,15),(30,15),(60,30),(25,65),(25,15) color green
handwritten plot -3*x + 1
handwritten 120 - 45 - 30