How To make my calculator do this trigonometry problem?

Question

So I have been using calculators at school recently and they have been preset to solve these trigonometric problems. I just bought my own and I can't figure out how to make it do these problems? We've been doing this course for only 2 days, so i might be a little confusing as I might have some things wrong. So, here is one problem: A right triangle, the right angle in an L shape, pointing to the right. The angle we need to know is in the top left, above the 90 degree angle. I have the opposite (8.7 yds) and adjacent (9 yds), making it a tangent. So, I have tanX = 9/8.7 , or x = tan (9/8.7). How do I do this on a calculator? And what do I have to make sure my calculator is doing it right? I'M NOT ASKING FOR AN ANSWER TO THE PROBLEM. (If you HAVE to give it to me, it'd be nice, but would only save me like 5 seconds lol)

Please help :C

Answer 1

TOA



x = tan (8.7 / 9) the tan is your problem to find x you need to use tangent inverse... its the button right above the tangent button and has a negative one behind it like a power





x = tan^-1(8.7 / 9)



oh yeah... forgot to add that you must have your calculator in degree mode. if it is a standard scientific calculator the default mode is degree. look for a little deg notation in the window. if you are using a graphing calc go into mode and take out of radian mode and put into degree mode by moving cursor down to radian over to degree and hit enter.

Answer 2

First of all, tan of an angle is opposite over adjacent, so the fraction would be 8.7/9.



tan X = 8.7/9

X = inverse tan (8.7 / 9)



Note the difference: tan of an angle gives the fraction, so if you want to know the angle, you need to "un-tan" the fraction - not that there is such a word!

So, you need to find the inverse tan button on your calculator. It may be two buttons, first "Inv" then "Tan", or it might be "2ndF" then "Tan" - basically, look for the word "tan" with a little "-1" above it.



To make sure you're doing it right, according to my calculator, it is

44.028978068920833507268967660963 degrees.

Answer 3

funny you ask, we just got off that lesson!



It depends on what kind of calculator you have. Here are your two options:



1.) if your calculator has a "parenthesis" function, you press:

- 2nd (top left corner)

- "tan" button

- 8.7 then the DIVIDE sign, and then hit 9.

- close the parenthesis and press ENTER. that should give you the answer of 44.0289780.....



BY THE WAY, tangent is equal to OPPOSITE over ADJACENT. you had it backwards :)



2.) if you dont have a calculator with the parenthesis function, you do this:

- divide 8.7 and 9. it should equal 0.966666666......

- then press the 2nd in the upper left hand corner.

-hit the "tan" button

- it should equal 44.02897.....



If you have problems with Trig, here is the easy way to remember it:



SOH

CAH

TOA



Sine=opposite/hypotenuse

Cosine= adjacent/hypotenuse

Tangent= opposite/adjacent



There you go buddy!

Answer 4

The truth is you don't need a $100 TI-84 calculator to do the trignometry that they teach you in school. The scientific calculator that they have coded into Microsoft Windows is sufficient. The graphing calculators do help you understand what the graphs look like, but aren't necessary for the majority of school work. Or you or your mom can get a simple $10 TI-30 and that should be sufficient for your math homework. I understand doing an arccos(42.7364°) is unreasonable without a calculator, but again, the calculator on your computer or a simple $10 scientific calculator should be able to do this. Don't rely on calculators, too many stupid people do. If you can supply me with an example from your text book where the calculator that comes in windows is insufficient, I may change my mind, but I got through all my ode (ordinary differential equations) and pde (partial differential equations) classes through college with what is equivalent to the TI-30s of today.

Answer 5

usually on a calculator if you need to find the angle you have to use inverse tan (or sine or cosine) which you can usually get by pressing the shift key followed by the tan (or sine or cosine) button

so to solve your problem you would type in

shift tan ( 9 / 8.7 ) =(or exe depending on the calculator)

this gives you roughly 45.97 degrees (to 2 dp)

Answer 6

if opposite is 8.7 and adjacent is 9 then tan x=8.7/9

you have to use tangent inverse which is tan^-1



so you plug in tan^-1(8.7/9)