Question

What is the cosine of a 30° angle?

Answer 1

Do you have a book with a list of cosine values?
Do you have a calculator with the cosine function?

Answer 2

umm

Answer 3

I have the TI-83 plus?

Answer 4

That might have the cosine function. (I'm not familiar with the TI-83)

Answer 5

Ya it does

Answer 6

Try using it

Answer 7

My answer has to be a sq root fraction

Answer 8

Hmmm, maybe they want you to actually calculate it.
I can help you.

Answer 9

The calculator on here has it

Answer 10

o nvm

Answer 11

I think its sq root 3

Answer 12

Here is a graphic

Answer 13

1/2

Answer 14

That is a 30-60-90 triangle.
In such a triangle the hypotenuse is exactly twice as big as the small side.

Answer 15

oo

Answer 16

So hypotenuse = 2
Opposite = 1

Then we need the Pythagoean Theorem to find the adjacent side
2^2 = 1^2 + adj^2
4 - 1 = adjacent side squared
3 = adjacent side squared

adjacent side = square root of 3
(we're not done yet)

Answer 17

Looking at the graphic, we see that the cosine of 30 degrees = adjacent side / hypotenuse
cosine of 30 degrees = (square root of 3) / 2
and there's your answer
It's that simple -- LOL

Answer 18

Ty, can u help me with 3 more?

Answer 19

Well let's try 1 more :-)

Answer 20

What is the cosine of a 30° angle?

Answer 21

You've already asked that

Answer 22

o

Answer 23

i meant tan

Answer 24

Okay tangent of 30 degrees
Look at the graphic

Answer 25

We know from the previous problem that the opposite side = 1
and the adjacent side = square root of 3
Therefore the tangent of 30 degrees = 1/(square of 3)

Answer 26

uh thats not a choice

Answer 27

What are the choices?

Answer 28

That equals the sq root of 3 / 3
(Don't know how they got that but it's correct
(SO is 1/sq root(3)

Answer 29

mk

Answer 30

Multiply 1/(sq root of 3) by the sq root of 3 and you get
sq root (3) / 3
:-)

Answer 31

ooooo

Answer 32

So can u help me with 2 more? or check my answers?

Answer 33

Sure - go ahead

Answer 34

What is the tangent of a 60° angle?

I put sq root 3

Answer 35

Well I made another graphic

Answer 36

is it sq root 3/2?

Answer 37

hyp = 2 adj = 1
from Pythagorean Theorem
hyp^2 = adj^2 + opp^2
opp^2 = hyp^2 - adj^2
opp^2 = 4 -1
opp^2 = 3
opposite side = sq root of 3
tan 60 = opp/adj
tan 60 = sq root of 3 / 1 = sq root of 3
Very good Root beer

Answer 38

No wait it's just square root of 3

Answer 39

o ok haha

Answer 40

You were right the first time

Answer 41

What is the sine of a 30° angle
I puy sq root 3/3

Answer 42

put*

Answer 43

Here's the new graphic
Remember the hypotenuse is 2
and the opposite side = 1
So, the sine of 30 degrees equals??

Answer 44

1/2?

Answer 45

That's right
By the way, here's an online calculator if you want to check the answers (and they are correct)
http://www.1728.org/trigcalc.htm

Answer 46

Incidentally, that's my website :-)

Answer 47

lol ok ty

Answer 48

u r welcome
May I have a medal?

Answer 49

Thanks :-)

Answer 50

np