10
5.5 Trigonometric/Geometric functions
Degree / Radian / Grad selector key
Used to calculate trigonometric and coordinate conversions.
The DRG key changes the angular mode.
Ex. To enter GRAD mode, depress the key twice.
“DEG” mode
Entries and answers are in decimal degrees. One degree equals 1/360 of a circle.
“RAD” mode
Entries and answers are in radians. One radian equals 1/2
π
of a circle.
“GRAD” mode
Entries and answers are in grads. One grad equals 1/400 of a circle.
Right angle conversions: 90° =
π
/2 = 100g
Angular unit conversion key
These keys convert the displayed number into an equivalent number of the next angular mode.
• If you are in Degrees mode, pressing these keys will convert the display into equivalent radians.
• If you are in Radians mode, pressing these keys will convert the display into equivalent grads.
• If you are in Grads mode, pressing these keys will convert the display into equivalent degrees.
Ex: 180 (in DEG mode) 3.141592654 (in RAD mode)
Trigonometric function key
sin key calculates the sine of angle ø.
cos key calculates the cosine of angle ø.
tan key calculates the tangent of angle ø.
NOTE: make sure your calculator is in the appropriate angle mode (DEG, RAD, or GRAD) before
calculation. Select the angle mode with the key (see above).
Inverse trigonometric function key
sin key calculates the arcsine of angle ø.
cos key calculates the arccosine of the angle ø.
tan key calculates the arctangent of the angle ø.
NOTE: Make sure your calculator is in the appropriate angle mode (DEG, RAD, or GRAD) before
calculation. Select the angle mode with the key (see above).
sin
cos
tan
B
C
A
sin ø = B/C
cos ø = A/C
tan ø = B/A
ø
sin
cos
tan
2ndF
2ndF
2ndF
sin
–1
cos
–1
tan
–1
(opposite)
(hypotenuse)
(adjacent)
DRG
DRG
DRG
DRG
DEG
RAD
GRAD
DRG
2ndF
DRG
▼
▼
2ndF
DRG
5. Calculator
functions,
continued
