Texas Instruments TI-89 Titanium User Manual page 758

Using Vectors to Determine Velocity
A small fishing boat leaves from the south bank of the Allegheny River and heads at a
80° angle with an engine speed of 20 knots. However, the eastward force of the current
carries the boat along so it actually travels at a 60° angle with the shore.
How fast is the current, and how fast does the boat actually travel?
1. Set the modes for
screen. (Show angles in degrees instead
of radians and display all digits with a
floating decimal point.)
Press: 3 D D D. On the Angle option,
select
2:DEGREE
option, select
Activities
as shown in this
Page 1
. On the Display Digits
.
E:FLOAT
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