4.1 – Angles on the TI-83+ calculator MODE Two calculator modes – degrees radians (use arrow keys to move cursor down and across) When the cursor is blinking over your selected mode: ENTER To exit mode: 2nd, QUIT Math 97 D.Sluys

2nd ANGLE ALPHA “ Entering DMS form Example: 64 degrees (D) 32 minutes (M) 47 seconds (S) For degrees and minutes use : 2nd ANGLE For minute sign use: ALPHA “ (the “ is above the + key)

Express 64.54 degrees in radians 180 degrees = radians Convert degrees to radians using ratios Express 30 degrees in radians As a number As a multiple of Express 64.54 degrees in radians

decimal degrees to radians in radian mode 180 degrees = radians Calculator will convert decimal degrees to radians in radian mode {In degree mode need to use ratios.}

180 degrees = radians Convert radians to decimal degrees using ratios

Calculator will convert radians to decimal degrees and/or DMS 180 degrees = radians Calculator will convert radians to decimal degrees and/or DMS in degree mode {in radian mode – use ratios}

DMS form conversions: In degree mode, convert decimal degree to DMS, and radians to DMS (need to stipulate radians)

(omit degree sign to get correct answer) But not radians to DMS In radian mode, convert decimal degree to DMS, (omit degree sign to get correct answer) But not radians to DMS (note wrong answers)

RADIAN mode DEGREE mode DMS form to other forms DMS form to radians DMS to radians (using ratios) DMS to decimal degrees (angle menu) (short-cut)

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