# trigonometry

posted by on .

a question just like this one was on one of my homeworks..i asked for help but i didn't understand the explanation..so i had to gues..nd now i have that kind of quesion again on my homework. pleease explain this thoroughly
find the value of s in the interval [0,pi/2] that makes the statement true
1. tan s= 6.86874202
thnks to whoever answers and explains it:)

• trigonometry - ,

you are told that
tan s = + 6.86874..
so by the CAST rule, the angle must be in the I or III quadrant.
but our domain is from 0 to pi/2 which is only quadrants I and II.

enter
inv tan or 2nd function tan
6.68742..
=

I got s = 1.42622 radians

• trigonometry - ,

ya see this somehow doesnt work on my calculator
[pi,3pi/2];tan s=1
so you have to enter inv tan 1??
confuusedd

• trigonometry - ,

let's try it with degrees first
set you calc to degrees

test #1
enter

tan
45
=

you should get 1

now work it backwards (the inverse)

at the top left you should have either an "INV" key or 2ndF key

enter:
2ndF
tan
1
=

you should get 45 degrees

If that doesn't work it could be that on your calc you have to enter the number first.

let me know if it worked.
If it worked, set your machine to radians and repeat the steps in the same way as noted above.

• trigonometry - ,

when i do tan 45 i get 1.6197..
do you know any site where i can use a calculator...

• trigonometry - ,

http://www.mathsisfun.com/scientific-calculator.html

• trigonometry - ,

thnks:)

• trigonometry - ,

yes, tan 45 radians = 1.6197

look for a key that says DRG, it will toggle your setting beteen degrees, radians and gradians

• trigonometry - ,

ya Damon already helped me understand the problem
i set it to radians. entered 1, atan and it equaled .785