HP 40gs User Manual page 226

hp40g+.book Page 44 Friday, December 9, 2005 1:03 AM
TRIGCOS
TRIGSIN
TRIGTAN
14-44
Typing:
2
TRIG(SIN(X) + COS(X)
gives:
2
Simplify using the cosines
TRIGCOS has as an argument a trigonometric
expression.
TRIGCOS simplifies this expression, using the identity
2 2
sin(x) +cos(x) = 1 to rewrite it in terms of cosines.
Typing:
4
TRIGCOS(SIN(X)
gives:
4 2
x ( ) x ( )
cos – cos + 2
Simplify using the sines
TRIGSIN has as an argument a trigonometric expression.
TRIGSIN simplifies this expression, using the identity
2 2
sin(x) + cos(x) = 1 to rewrite it in terms of sines.
Typing:
4
TRIGSIN(SIN(X)
gives:
4 2
x ( ) x ( )
sin – sin + 2
Simplify using the tangents
TRIGTAN has as an argument a trigonometric expression.
TRIGTAN simplifies this expression, using the identity
2 2
sin(x) + cos(x) = 1 to rewrite it in terms of tangents.
Typing:
4
TRIGTAN(SIN(X)
gives:
4
⋅ x ( ) ⋅ x ( )
2 tan + 3 tan
------------------------------------------------------------------ -
4
x ( ) ⋅ x ( )
tan + 2 tan
2
+ 1)
2
+ COS(X) + 1)
2
+ COS(X) + 1)
2
+ COS(X) + 1)
2
+ 2
2
+ 1
Computer Algebra System (CAS)