HP 40gs User Manual page 225

hp40g+.book Page 43 Friday, December 9, 2005 1:03 AM
TLIN
TRIG
Computer Algebra System (CAS)
gives:
3
4·cos(x) –3·cos(x)
Linearize a trigonometric expression
TLIN has as an argument a trigonometric expression.
TLIN linearizes this expression in terms of sin(n x) and
cos(n x).
Example 1
Typing:
TLIN(COS(X) · COS(Y))
gives:
1 1
⋅ ( ) ⋅
-- - -- -
cos x y – + cos
2 2
Example 2
Typing:
3
TLIN(COS(X) )
gives:
1 3
⋅ ( 3 x ⋅ ) ⋅
-- - -- -
cos + cos
4 4
Example 3
Typing:
2
TLIN(4·COS(X) -2)
gives:
⋅ ( 2 x ⋅ )
2 cos
Simplify using sin(x)
TRIG has as an argument a trigonometric expression.
TRIG simplifies this expression using the identity
2 2
sin(x) + cos(x) = 1.
( )
x + y
x ( )
2 2
+ cos(x) = 1
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