Secant, cosecant and cotangent
Get sec, csc and cot by taking the reciprocal of cos, sin and tan.
There are no sec, csc or cot keys. Use the reciprocals: sec x = 1 ÷ cos x, csc x = 1 ÷ sin x and cot x = 1 ÷ tan x.
Example: sec 40 degrees = 1 ÷ cos 40 = 1.305407289.
Classic Graphing 84
Start on the main screen: Press 2nd then mode (QUIT) to get back to the home screen. Pressing clear on a menu also backs out of it.
Switch to degrees.
mode▼▼▶enter2ndQUITmodeType cos(40), close the bracket, then press the x⁻¹ key. That divides 1 by the value.
cos40)x⁻¹enter
You should see1.305407289
Classic Scientific 30
Start on the main screen: Press 2nd then mode (QUIT) to leave any menu or screen and return to the calculation screen.
This model starts in degrees. Type cos(40), close the bracket and press the x⁻¹ key.
cos40)x⁻¹enter
You should see1.305407289
Natural Scientific 991
Start on the main screen: Press MENU, then 1 (Calculate) to return to the main calculation screen. AC clears the line you are on.
The calculator starts in degrees. Type cos(40), close the bracket and press the x⁻¹ key, then =.
cos40)x⁻¹=
You should see1.305407289
Natural Color Graphing
Start on the main screen: Press MENU then 1 to open Run-Matrix, the main calculation screen. Press EXIT to back out of a bar or screen, and SHIFT then EXIT (QUIT) to return to the app start.
Set degrees. Type cos(40) and close the bracket.
SHIFTSET UPMENU▼▼F2EXITcos40)Press SHIFT then the ) key for x⁻¹, then EXE.
SHIFTx⁻¹)EXE
You should see1.305407289
Classic CAS
Start on the main screen: Press home to open the Home menu (Calculator, Graphs, Settings, and more). Choose Calculator, or press esc to go back to the calculation page.
Set degrees. Type 1 ÷ cos(40) and press ctrl enter for a decimal.
menu9▼▶enterenterenter1÷cos40)ctrl≈enter
You should see1.30541
RPN Scientific 15
Start on the main screen: There is no menu to leave. Press the back arrow to clear a number you are typing, or CLx (g then back arrow) to clear the X register.
Key in 40, press COS, then the 1/x key.
40COS1/x
You should see1.3054
RPN Advanced 42
Start on the main screen: Press EXIT (once or twice) to close any menu and return to the plain stack view of Y and X.
Key in 40, press COS, then the 1/x key.
40COS1/x
You should seex: 1.3054
RPN Power 48
Start on the main screen: Press ON to cancel what you are typing, then use the stack view. Open the MODE or VAR menu any time; the stack is always shown above the menu row.
Choose DEG. Key in 40 and press COS.
MODEF540COSPress the left shift and the ÷ key for 1/x.
◀1/x÷
You should see1.30540728933
Tips
- Do not confuse cos⁻¹ (the inverse function, giving an angle) with 1 ÷ cos (the secant). They are different.
- When you are typing a longer formula, write 1 ÷ cos(x) in full so the order is clear.