Question

Can you guys help me please??
cos(pi/6 + (inverse)cos 3/4)

Answer 1

\[\cos(x+y)=\cos(x)\cos(y)-\sin(x)\sin(y)\]

Answer 2

\[\cos(\frac{\pi}{6}+\cos^{-1}(x))=\cos(\frac{\pi}{6})\cos(\cos^{-1}(x))-\sin(\frac{\pi}{6})\sin(\cos^{-1}(x))\]

Answer 3

some of these are numbers you may know
for example \(\cos(\frac{\pi}{6})=\frac{\sqrt3}{2}\)

Answer 4

yup :)

Answer 5

also
\[\cos^{-1}(\cos(x))=x\]

Answer 6

\[\sin(\frac{\pi}{6})=\frac{1}{2}\]

Answer 7

only one left to figure out is what is
\[\sin(\cos^{-1}(x))\]

Answer 8

you know what that is?

Answer 9

oooh i misread the question
the second part is \(\cos^{-1}(\frac{4}{5})\) right

Answer 10

yeah

Answer 11

even easier
\[\cos(\frac{\pi}{6})\cos(\cos^{-1}(\frac{4}{5}))-\sin(\frac{\pi}{6})\sin(\cos^{-1}(\frac{4}{5}))\]

Answer 12

I thought that you do \[\sin(\cos ^{-1}3/4)\]

Answer 13

which = sin v

Answer 14

yeah that is all that is left

Answer 15

oh okay

Answer 16

we got
\[\frac{\sqrt3}{2}\times \frac{3}{4}-\frac{1}{2}\times \sin(\cos^{-1}(\frac{3}{4})\]so far

Answer 17

soo.. \[\sqrt{1-\cos^2}v ?\]

Answer 18

yeah that will do it
i do it by drawing a triangle

Answer 19

ooo I wanna draw a triangle
how do you do it that way?

Answer 20

you're so cool..

Answer 21

there is a picture of an angle whose cosine is \(\frac{3}{4}\) all that is missing is the third side, which you find via pythagoras
it is
\[\sqrt{4^2-3^2}=\sqrt7\]

Answer 22

yeah cool, why i am on dorky math site at night, but thanks...

Answer 23

haha I think you're awesome :p

Answer 24

soo you get sqrt(7)/4?

Answer 25

making
\[\sin(\cos^{-1}(\frac{3}{4}))=\frac{\sqrt7}{4}\]

Answer 26

right what you said

Answer 27

B)

Answer 28

you will get the same answer the other way

Answer 29

the rest you basically plug in and its all algebra right?

Answer 30

shush

Answer 31

i would call it arithmetic, but yes, just plug them in

Answer 32

i wanna do it :P

Answer 33

fine
good idea
let me know what you get

Answer 34

is it \[(3\sqrt{3}-\sqrt{7})/8\]?

Answer 35

not telling

Answer 36

comeonnnnn

Answer 37

haha

Answer 38

ok yes it is

Answer 39

it has to beee

Answer 40

yay <3

Answer 41

yes you are right

Answer 42

haha thanks :)

Answer 43

what's your name mister satellite?

Answer 44

never seen some one excited over a trickonometry problem
glad you enjoy them

Answer 45

haha

Answer 46

" trickonometry"

Answer 47

actually don't tell me your name you might get in trouble :P

Answer 48

Bye :p

Answer 49

i am just satellite73
bye

Answer 50

You're just like a superhero...
just satellite73 :p

Answer 51

yikes how many picture you got?

Answer 52

sorry haha :p

Answer 53

just gotta find the right one ya know :p

Answer 54

this looks good