WOLFRAM
|
DEMONSTRATIONS PROJECT
T
a
n
g
e
n
t
P
l
a
n
e
t
o
a
S
p
h
e
r
e
l
o
n
g
i
t
u
d
e
θ
0
l
a
t
i
t
u
d
e
ϕ
0
z
1
T
h
e
e
q
u
a
t
i
o
n
o
f
t
h
e
t
a
n
g
e
n
t
p
l
a
n
e
t
o
a
s
p
h
e
r
e
o
f
r
a
d
i
u
s
r
a
n
d
c
e
n
t
e
r
a
t
t
h
e
o
r
i
g
i
n
a
t
l
a
t
i
t
u
d
e
θ
a
n
d
l
o
n
g
i
t
u
d
e
ϕ
i
s
x
c
o
s
(
θ
)
s
i
n
(
ϕ
)
+
y
s
i
n
(
θ
)
s
i
n
(
ϕ
)
+
z
c
o
s
(
ϕ
)
=
2
r
.