Texas Instruments TI-89 Voyage 200, User Manual

Page: 778 / 1008

Activities 778
3. Enter vectors describing the initial path of
the boat, water current, and resultant path
of the boat.
Store these vectors as
i
,
c
, and
r
. Use the
value
a
for the unknown speed of the
current. Use the value
b
for the speed of
the boat.
Enter:
[20,80
¡
]
!
i
[a,0 ¡ ]
!
c
[b,60°]
!
r
Vectors are commonly written in either polar
or rectangular form, so it is useful to convert
polar vectors into rectangular form.
4. Define function
p2r
.
Enter:
Define p2r(x)=[x[1,1]*cos(x[1,2]),
x[1,1]*sin(x[1,2])]