Maths help. plz

2009-06-12 22:14:02

#1

Little BaBy JESUS: m8; +394|6572|'straya

Now I know there have been a thousand of these but I really need this.

Heres a couple questions from a revision booklet I was given for my maths exam on monday.
Its not these questions in particular so much, but i've forgotten all the concepts behind them. I'm really fucking tired and have completely mind blanked. If someone could do these step by step and explain any concepts behind them it would be great. (I realise they are easy, but i've seriously just blanked) Ive provided the answers so you know if your right

1. If sin θ=0.7. and 0°< θ <90°, find correct to three decimal places
a) cos θ
b) tan θ

ANSWER: a) 0.714
b) 0.980

2. Solve the equation 2 sin^2 X = som X over the domain 0 ≤ X ≤ 2pi.

ANSWER: X=0,pi/6, pi, 5pi/6, 2pi

(the pi symbol was being gay lol)

THANKS TO ANYONE WHO HELPS

2009-06-12 22:25:52

#2

Narupug: Fodder Mostly; +150|6020|Vacationland

Little BaBy JESUS wrote:
Now I know there have been a thousand of these but I really need this.

Heres a couple questions from a revision booklet I was given for my maths exam on monday.
Its not these questions in particular so much, but i've forgotten all the concepts behind them. I'm really fucking tired and have completely mind blanked. If someone could do these step by step and explain any concepts behind them it would be great. (I realise they are easy, but i've seriously just blanked) Ive provided the answers so you know if your right

1. If sin θ=0.7. and 0°< θ <90°, find correct to three decimal places
a) cos θ
b) tan θ

ANSWER: a) 0.714
b) 0.980

2. Solve the equation 2 sin^2 X = som X over the domain 0 ≤ X ≤ 2pi.

ANSWER: X=0,pi/6, pi, 5pi/6, 2pi

(the pi symbol was being gay lol)

THANKS TO ANYONE WHO HELPS

Well for the first one you know that sin=opposite over hypotenuse, 7/10, so just figure that out then use pythagorean to go from there to find Cos adjacent over hypoteneuse and tangent opposite over adjacent.
Opposite=7
Adjacent=sqrt51
Hypoteneuse=10
so A is sqrt51/10
and b is 7/sqrt51
Hope this helps!

2009-06-12 23:21:11

#3

xBlackPantherx: Grow up, or die; +142|6766|California

Well, if it's based off of the unit circle in any way then you can go from there. If it is sin=y coordinate and cos=x coord. But yea like ^^ said, it's based off of pythag thm. S_OH C_AH T_OA (Sin = opposite/hypot., Cos = Adjacent/Hypot., Tan = Opposite/Adjacent). a² + b² = c².

https://analoglogic.net/everobotics/projects/roboMagellan/img/UnitCircle.gif

Last edited by xBlackPantherx (2009-06-12 23:24:52)

2009-06-13 00:14:21

#4

DrunkFace: Germans did 911; +427|7105|Disaster Free Zone

1. sin^-1 0.7 = 44..42.....
a) cos 44.42.... = 0.714
b) tan 44.42.... = 0.980

Don't round before the final answer always keep as many significant figures in your calculator as possible, thats what the "..." mean I just couldn't be bothered writing it all out.

2. Solve the equation 2 sin^2 X = som X over the domain 0 ≤ X ≤ 2pi. som = sin I assume?

2sin x = 0, 1
sin x = 0, 0.5
x = 0, π/6, 5π/6, π, 2π
Or 0, 30, 150, 180, 360 Degrees.

Last edited by DrunkFace (2009-06-13 00:27:13)

2009-06-13 03:16:13

#5

Little BaBy JESUS: m8; +394|6572|'straya

Thanks guys, I just got home from work and am absolutely fucked... so ill go over it all tomorrow when i'm hard at study

2009-06-13 03:19:55

#6

usmarine: Banned; +2,785|7185

Next for you: Grammar 101

2009-06-13 03:21:26

#7

Little BaBy JESUS: m8; +394|6572|'straya

usmarine wrote:
Next for you: Grammar 101

Because a gaming forum is totally a place where exact punctuation and grammar is essential.

2009-06-13 03:55:13

#8

usmarine: Banned; +2,785|7185

Little BaBy JESUS wrote:
usmarine wrote:
Next for you: Grammar 101
Because a gaming forum is totally a place where exact punctuation and grammar is essential.

Well its a great place for maths plz also

2009-06-13 04:40:23

#9

Little BaBy JESUS: m8; +394|6572|'straya

usmarine wrote:
Little BaBy JESUS wrote:
usmarine wrote:
Next for you: Grammar 101
Because a gaming forum is totally a place where exact punctuation and grammar is essential.
Well its a great place for maths plz also

Thank you for your contribution usmarine, it really has helped and enlightened me.

2009-06-13 04:42:15

#10

usmarine: Banned; +2,785|7185

welcome. and i thank you for all of yours to me.

2009-06-13 04:43:19

#11

Cheez: Herman is a warmaphrodite; +1,027|6862|King Of The Islands

Little BaBy JESUS wrote:
usmarine wrote:
Next for you: Grammar 101
Because a gaming forum is totally a place where exact punctuation and grammar is essential.

Good attitude.

My state was founded by Batman. Your opinion is invalid.

2009-06-13 04:50:20

#12

GC_PaNzerFIN: Work and study @ Technical Uni; +528|6838|Finland

Ahh have fun with that shit. It was 2 years ago when I last time calculated those.

3930K | H100i | RIVF | 16GB DDR3 | GTX 480 | AX750 | 800D | 512GB SSD | 3TB HDD | Xonar DX | W8

BF2S Forums Maths help. plz

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