Question

How do we find the value of sin, cos and other trigonometric functions?

Answer 1

uhmm do you mean the like sin(30) , cos(30) and all those good stuffs?

Answer 2

yes I mean like how do we know the value of sin in a function like f = sin (x) / x ?

Answer 3

well that depends on what x is

Answer 4

well it depends on your x

Answer 5

strange...

Answer 6

suppose x value = 2

Answer 7

then it would be \(\large \frac{\sin (2)}{2}\) then you'll have to use a calculator

Answer 8

or some crazy manipulative trigonometric theorems

Answer 9

Or calculus :)

Answer 10

But probably just use a calculator :)

Answer 11

so we always suppose to use calculator whenever we see sing cos tan signs?

Answer 12

or is there any way to calculate the values of trig functions?

Answer 13

well you could draw a triangle and measure the ratio of side lengths

Answer 14

Well there's a way to calculate them, because the calculator has to calculate them, and you could do the same thing. But it's usually easiest to use a calculator except for in certain cases. If it's one of the common ones, like \(\pi/6, \pi/4, \pi/3 \), etc, then you can solve using unit circle or just memorize them.

Answer 15

can you please give me a link to any website where I can find about this?

Answer 16

http://en.wikipedia.org/wiki/Unit_circle

Answer 17

There are special angles where sin and cos are easy to find. Any multiple of 90 degrees is pretty simple, and these are the ones you really should be comfortable with.

Answer 18

http://www.clarku.edu/~djoyce/trig/

Answer 19

Here's what happens to cos at different multiples of 90:
cos(0) = 1
cos(90) = 0
cos(180) = -1
cos(270) = 0
cos(360) = cos (0) = 1

And sin:
sin(0) = 0
sin(90) = 1
sin(180) =0
sin(270) = -1
sin(360) = sin(0) = 0