Calulator settings... (1 Viewer)

[countrydude]

Hey, i am doing this question from past papers and in the back it says:

cos (pie) is equal to -1

on my calc it says that the cos of pie is 0.998497...

whats doing here?

i have my calculator set in deg

what am i doing wrong?

thanks.


oh btw, i am doing past papers and i seem to get everything wrong, it feels like i am going to fail this test, is this just normal hsc feelings or what?

 

[Jumbo Cactuar]

OMG!!!

 

[Jumbo Cactuar]

Ever heard of radians mode ??!!?!

pi being a number of degrees of radians!

 

[countrydude]

ahhhh, thanx 4 help, yer i am a dumass at this shit

 

[Jumbo Cactuar]

no worries mate, my friend is such a dummy, I doubt you will come last ... just as well you sorted that little dousy out b4 the real thing!

 

[cakes]

hahah fuck ... when do you use radians mode? =\

 

[Winston]

Originally posted by cakes
hahah fuck ... when do you use radians mode? =\

lol when your dealing with radians lol...

like the area of a minor i thinkt that's it

the 1/2r^2(theta -sintheta)

 

[Rahul]

or you can just sub in 180 where it says pi.
eg: pi/2 = 180/2 = 90.
and just use that substitution in deg mode

 

[iambored]

i normally sub i in, it saves confusion with modes

only use rad for approximate areas (trapeziodal and simp) with calculus

if there is another time i should be changing it tell me!

 

[Rahul]

"if there is another time i should be changing it tell me!" i dont follow

i never use rad

 

[kimmeh]

use normal like 90 degrees 45 degrees
then change to radians by using the fraction button.. or dividing it by 180 then its thaat vaule times pi

so. 90 degrees would be


90/180 = 1/2 x (pi) = pi/2 thats how i do it.. i hate the radian mode..confuses me even more

 

[evilc]

in 3 unit, newton's approximation to the root questions that involve trig functions is one that you've gotta use radians for, and arc lengths as well....i was doing that stuff today in first year surveying work.

 

[Rahul]

evilc, i think you may have it confused with something else [or have i? ]

i certainly havent used radians for newtons method

 

[evilc]

i dont think i'm confused, i think it mentions it in geha's 50 3unit tips or something, coz i remember last year getting a few newtons method questions wrong coz of not having calculator in radians.

 

[Rahul]

for what eactly did you use radians for?
you may have had that as the setting, but it wouldnt have affected the answer. its only used when dealing with trignometry...

 

[evilc]

yeah, sorry rahul thats what i meant, i just didnt make it clear..

eg. sinx - x = 0 sorta thing

for any non trig functions, radians or otherwise would have no impact at all on answer

 

[Rahul]

lol, i was worried for a sec.

the "shit, never heard of this before" went through my mind