Question

Trigonometry Incoming: 15 Questions, some I can answer, some I can't... http://prntscr.com/45bljs http://prntscr.com/45blql http://prntscr.com/45blxl http://prntscr.com/45bm3b http://prntscr.com/45bm7a http://prntscr.com/45bmcd http://prntscr.com/45bmh8 http://prntscr.com/45bmmo
@satellite73
@dumbcow

Answer 1

I know it looks like my entire practice exam, but I can do some of them and I can do some of them partially.

Answer 2

I can answer 16-20, that's why I didn't include them.

Answer 3

ok which ones do you need most help on

Answer 4

Let's start with 1, so I can get warmed-up.

Answer 5

ok #1 is pretty easy if you understand how to set up a triangle and use SOH CAH TOA

Answer 6

Ok, how would I find the adj?

Answer 7

Pythagorean?

Answer 8

yes

Answer 9

If anyone can start to explain these that would be great! I have to go somewhere real quick. Be back in 20, if you can help then, @dumbcow

Answer 10

well at least finish answering #1
did you get the adjacent side?

Answer 11

Working on it. One sec.

Answer 12

I got 1. \[\sqrt{17}^2 - 4^2 = 1\]

Answer 13

correct ... then cot = ?

Answer 14

1/4

Answer 15

yep

Answer 16

Alright, I will be back, just have to run to the corner store.

Answer 17

*walk*

Answer 18

k

Answer 19

for #2
\[\sin(a-b) = \sin a \cos b - \sin b \cos a\]
plug in a = pi/2 , b = x

cot = 1/tan = cos/sin

Answer 20

@dumbcow I'm back if you want to come back on...

Answer 21

@mathstudent55 Can you help me with some of this? Starting @ Q3

Answer 22

what did you get for #2 after simplifying

Answer 23

#3 is just like #1
draw triangle and use pythagorean thm

Answer 24

Sorry, had a little internet derp.

Answer 25

I got locked out of the practice test, I'm having the FLVS redo it now.

Answer 26

We can keep going for now, I may just be in and out trying to reset the test.

Answer 27

For two I'm stuck at: 2Cosx - (Sin(π/2)Cosx - SinxCos (π/2))

Answer 28

ok but generally all the problems will be similar so if you learn how to solve these you can do the others no matter how many times they change the problems around :)

Answer 29

Sometimes they don't change, which would be heaven...

Answer 30

ok just finish evaluating .... what is sin(pi/2) ?
cos(pi/2)?

Answer 31

Real number?

Answer 32

OH
ON THE UC

Answer 33

yes you should have these memorized but here is a reference
http://en.wikipedia.org/wiki/Unit_circle#mediaviewer/File:Unit_circle_angles_color.svg

Answer 34

So 1 and 0?

Answer 35

yes

Answer 36

Is that it?

Answer 37

so replace the sin π/2 with 1?

Answer 38

correct and cos(pi/2) = 0

Answer 39

so the answer cosx?

Answer 40

correct

Answer 41

Ok, 3.

Answer 42

draw triangle and use pythagorean thm

Answer 43

Tan x =6

Answer 44

Do you have skype? I feel it would be easier through skype...

Answer 45

no sorry

Answer 46

alright. Let's keep going! Q4

Answer 47

wait show me your triangle ... tan x = 6 is incorrect

Answer 48

1/6. Right?

Answer 49

Sec = hyp/adj

Answer 50

1/6 = tan x

Answer 51

good :)

oh and its negative because its given that sin<0

Answer 52

oh. so -1/6

Answer 53

yes

ok #4 use trig identity:

sec^2 = tan^2 + 1

Answer 54

but it's + 2?

Answer 55

http://en.wikipedia.org/wiki/Pythagorean_trigonometric_identity#Tabulation_of_derivations

Answer 56

right, therefore its not true

no solution

Answer 57

ok.

Answer 58

#5 I refer you to the unit circle

Answer 59

for Q4, do we count the negative version of sqrt(3)/2?

Answer 60

no it would have a neg sign if it was meant to be negative

Answer 61

ok. Done. Q6

Answer 62

calculator for Q6?

Answer 63

\[\sin(a+b) = \sin a \cos b + \sin b \cos a\]
pick an a and b that add up to 75