Question

how can i do sin cos and tan on a non graphing calculator

Answer 1

You can always get a graphing calculator online but there should be buttons on your calculator saying sin cos and tan

Answer 2

its for my class were not allowed to use graphing calculators or any calculators with a sin cos or tan function

Answer 3

In that case, if you know the sides, you use this:
tangent=opp/adj
sine=opp/hyp
cosine=adj/hyp

Answer 4

i know that lol. but if i had that opp and the hyp how would i find what the angle equals with out entering in sin(opp/hyp) into a calculator

Answer 5

you mean without entering in sin^{-1}(opp/hyp)

Anyways if the value you get for opp/hyp is on the unit circle you can use the unit circle.
Or if the angle in on the unit circle you can use the unit circle
sometimes you can rewrite the angle so that the angles show on the unit circle

Answer 6

how would i rewrite the angles?

Answer 7

like for eample if i had sin 41?

Answer 8

darn i hit my mouse button after typing all of that
one sec...

Answer 9

The best I can do with sin(41) is approximate it
however if you were asking for something like sin(75) I could get you exact value
by first rewriting 75 as a sum of angles that do show on the unit circle
like sin(30+45)
sin(30)cos(45)+sin(45)cos(30)
\[\frac{1}{2} \cdot \frac{\sqrt{2}}{2}+\frac{\sqrt{2}}{2} \cdot \frac{\sqrt{3}}{2} =\frac{\sqrt{2}+\sqrt{6}}{4} \text{ this is the exact value of } \sin(75^o)\]

now with sin(41) I said earlier I could approximate it
I know sin(41) is between sin(30) and sin(45) because 41 is between 30 and 45

\[\sin(30^o)< \sin(41^o)< \sin(45^o) \\ \frac{1}{2} < \sin(41^o) <\frac{\sqrt{2}}{2} \\ \text{ so I would make the guesstimation that } \sin(41^o) \approx \frac{1.3}{2}=\frac{13}{20}\]
now this is definitely an approximation
because sin(41) is definitely irrational, not rational

Answer 10

when I enter this into a calculator for sin(41) I get something like .656

and 13/20 is .65

Answer 11

So it isn't a bad approximation

Answer 12

thank you so much for your help

Answer 13

Refer to the Mathematica generated plot attached.