How can i find angle with x-axis of a plot in matlab?

my plot curve is y = p1*x^2 + p2*x + p3

Coefficients:

p1 = 0.00053537

p2 = -8.1393e-018

p3 = -0.00044699

i want to find each point's angle with x axis . . .

Answer 1

[Azzi Abdelmalek]

p1 = 0.00053537
p2 = -8.1393e-018
p3 = -0.00044699
x=0:0.1:10
y = p1*x.^2 + p2*x + p3
angles=angle(x+j*y)

[Ali]

thanks a lot.

Answer 2

[Jan]

Points do no have angles.

Do you want the slope? You can achieve this by deriving the polynomial:

slope = 2 * p1 * x + p2

[Ali]

points definitely do not have angles. . . what i said was the angle of curve at that point with x-axis