Trigonometry and Your Calculator

Trigonometry and Your Calculator

This will show you how to use your calculator to do trigonometry calculations.

Which Calculator Do I Need?

• iPhone - Download GraphNCalc83

• Android - Download wabbit.emu

• OR ANY Texas Instruments Calculator Ti-83 or higher

For Android users...

wabbit.emu install information

• Select "Help me create a ROM using open source software"

• Select "TI-84 PLUS C SE" or any other calculator you want

• DO NOT CLICK DOWNLOAD! There are advertisements on these screens so just choose "NEXT" at the very bottom of the screen

• Wait and wait some more...

THIS IS FOR EVERYONE!

IF YOU SKIP THIS STEP ALL YOUR ANSWERS WILL BE WRONG!!!

• Hit the [ON] button

• Hit [MODE]

• Using the arrow keys, move the cursor down and over until it is on top of the word "Degree"

• Hit [Enter]

• "Degree" should now be darkened

• Hit [2ND] then [MODE] ..this is the quit button. Hitting [2nd] activates all the things in yellow above the keys. Quit is in yellow.

Multiple Choice

Lets check to see if you followed all the steps correctly...

Type the following:

SIN 3 0 ) [ENTER]

What should show on your screen is:

sin(30)

Select the number below that you see on your screen.

• 0.5

• -.988031624

If you got the last problem wrong then you did not set up the calculator correctly!! I told you this would happen...

• Hit the [ON] button

• Hit [MODE]

• Using the arrow keys, move the cursor down and over until it is on top of the word "Degree"

• Hit [Enter]

• "Degree" should now be darkened

• HIt [2ND] then [MODE] ..this is the quit button. By hitting the [2nd] key you have activiated all the words in yellow. Quit is in yellow.

Multiple Choice

Lets check again to see if you followed all the steps correctly...

We are going to calculate tan(45)

Type the following:

TAN 4 5 ) [ENTER]

What should show on your screen is:

tan(45)

Select the number below that you see on your screen.

• 1.619775191

• 1

Multiple Choice

Calculate the following:

cos(60)

• 0.5

• -0.952

• 0.866

• 1.732

Multiple Choice

The square root is a colored symbol above the $x^2$  key.  To activate any colored item you must hit the [2ND] button first.  The color of the button should match the words above the key.

We are going to calculate  $\sqrt{3}$  

Type the following: [2nd]   $x^2$  3   [RIGHT ARROW] [ENTER]

You should see the following:   $\sqrt{3}$   

BTW Square Root needs [RIGHT ARROW] to get you out from under the square root.  You will see why next.

What answer do you see on the screen

• 9

• 1.73205

• ERR: NONREAL ANS

• ERR: SYNTAX

Multiple Choice

The square root,  $\sqrt{ }$  , is a colored symbol.. it is above the [ $x^2$ ]  key.

We are going to calculate the following:   $\frac{\sqrt{3}}{2}$  

Type the following: [2nd]   $x^2$  3  [ RIGHT ARROW]   $\div$  2  [ENTER]

You should see the following:   $\sqrt{3}$ /2
DID YOU HIT THE [RIGHT ARROW] BEFORE THE DIVIDE KEY?

What answer do you see on the screen?

• 4.5

• 0.866025

• ERR: NONREAL ANS

• ERR: SYNTAX

Multiple Choice

Let's see if you are really getting this!

You will have to find the button!  LOOK ABOVE THE [SIN] KEY!  THIS IS NOT SINE!  It is very different.

LOOK AT THE EQUATION CAREFULLY!  The key is above [SIN]! ........ Where you put the "(" and  ")" is IMPORTANT!

 $\sin^{-1}\left(\frac{\sqrt{\left(3\right)}}{2}\right)$  

• 60
  

• ERR: DOMAIN

• 0.0302

• 0.015114

Multiple Choice

Calculate the following:

 $\tan^{-1}\left(\sqrt{\ 2}\right)$  

• 0.955316

• 54.7356

• 6.33411

• 0.024688

Multiple Choice

 $\sin\left(37\degree\right)=$  

• 0.73541

• 0.79864

• 0.6018

• -0.64354

Multiple Choice

 $\tan^{-1}\left(\frac{\sqrt{2}}{2}\right)$  

Where you put the  "(" and ")" is IMPORTANT!  
After  $\sqrt{2}$   you must use a right arrow before you divide!  Be sure to close the parenthesis!!  It is a good habit to get into. 

• 35.26439

• 45

• 0.017455

• 0.012342

Fill in the Blank

Calculate the following:

 $\tan\left(\frac{13}{5}\right)$  

ROUND to three decimal places and type the answer below.

Fill in the Blank

Calculate the following:

 $\sin^{-1}\left(0.789\right)$  

ROUND to three decimal places and type your answer below.

Fill in the Blank

Calculate the following:

 $\cos\left(\frac{21}{\sqrt{3}}\right)$  

ROUND to three decimal places and type your answer below.

REVIEW

• Mode needs to be set to Degree

• To activate keys in yellow hit the [2ND] key

• Square root needs "(" and ")" to be used

•  $\sin\left(x\right)$  and  $\sin^{-1}\left(x\right)$  are different things

• If you have a [NO] button, your calculator is upside down ;-)