207.sagews

V(x,y) = <x, -y>

Syntax Error: V(x,y) = <x, -y>

v = [(sin(x),x) for x in srange(-2*float(pi),2*float(pi),0.1)]

line(v)

plot_vector_field( (-x, -y+x^2), (x, -4, 4), (y, -4, 8))

Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/home/sage/sagenb/sage_notebook/worksheets/cemeyer/0/code/4.py", line 7, in <module> exec compile(ur'plot_vector_field( (-x, -y+x**_sage_const_2 ), (x, -_sage_const_4 , _sage_const_4 ), (y, -_sage_const_4 , _sage_const_8 ))' + '\n', '', 'single') File "/home/sage/sage/local/lib/python2.5/site-packages/SQLAlchemy-0.4.6-py2.5.egg/", line 1, in <module> NameError: name 'y' is not defined

vars("x,y")
plot_vector_field( (-x, -y+x^2), (x, -4, 4), (y, -4, 8))

Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/home/sage/sagenb/sage_notebook/worksheets/cemeyer/0/code/5.py", line 7, in <module> vars("x,y") TypeError: vars() argument must have __dict__ attribute

x,y = var("x,y")

p1 = plot_vector_field( (x, -y), (x, -4, 4), (y, -4, 4))

var('t')
p2 = parametric_plot((e^(t+ln(1)), e^(ln(1) - t)), -1.25, 1.25)
p3 = text("x", (1,1), rgbcolor=(1,0,0))
show(p1 + p2 + p3)

parametric_plot((t^3, t), 0, 2)

(1/54)*(9*(2^4)+1)^(3/2)

145*sqrt(145)/54

integral((t+2)*(2*t)+(2-t)*2,t,0,1)

17/3

32/5+9*4-80/3

236/15