This discussion is closed.
djwarfield
Badges: 0
#1
Report Thread starter 16 years ago
#1
Got a couple problems if you could help me out:

problem 1:

csc x/cot x - cot x/csc x = tan x/csc x

problem 2:

cos2y = 1-tan(squared)y/1+tan(squared)y

got a couple others if yer up to it
0
Mr White
Badges: 0
Rep:
?
#2
Report 16 years ago
#2
I find that a library card is generally good for proving your identity with.
0
felixjmorgan
Badges: 0
Rep:
?
#3
Report 16 years ago
#3
i have a fake id if you want it. and i know someone who can get you a fake apssport for £300 if yo want...


soz. i dont know tbh
0
theone
Badges: 0
Rep:
?
#4
Report 16 years ago
#4
(Original post by djwarfield)
Got a couple problems if you could help me out:

problem 1:

csc x/cot x - cot x/csc x = tan x/csc x

problem 2:

cos2y = 1-tan(squared)y/1+tan(squared)y

got a couple others if yer up to it
problem 1:

csc x = 1/sinx. cot x = cos x / sin x. So cscx/cotx - cotx/cscx = 1/cosx - cosx = 1-cos^2x/cosx = sin^2x/cosx = tanx/cscx.

2: 1-tan^2y/1+tan^2y = 1-tan^2y/sec^2y = cos^2y - sin^2y = cos2y.
0
djwarfield
Badges: 0
#5
Report Thread starter 16 years ago
#5
Heres another that kinda gets me....

Find all angles theta, for 0<theta<360degrees, that satisfy the equation:
2csctheta+1=-2


thanks again
0
theone
Badges: 0
Rep:
?
#6
Report 16 years ago
#6
(Original post by djwarfield)
Heres another that kinda gets me....

Find all angles theta, for 0<theta<360degrees, that satisfy the equation:
2csctheta+1=-2


thanks again
2csc x = -3 so csc x = -3/2 so sinx = -2/3 so x = arcsin (-2/3) and work out any other solutions...
0
djwarfield
Badges: 0
#7
Report Thread starter 16 years ago
#7
thanks....I had some notes written down so I just remebered how to do it...

ok one more then ill leave you alone

find the angle between vectors u = (2,5) and v = (-2,4)

thanks again
0
DanielW
Badges: 0
#8
Report 16 years ago
#8
(Original post by djwarfield)
thanks....I had some notes written down so I just remebered how to do it...

ok one more then ill leave you alone

find the angle between vectors u = (2,5) and v = (-2,4)

thanks again
u.v = modulus(u)modulus(v)cos(theta), where theta is the angle between them.

modulus u = sqrt(2^2+5^2)=sqrt29

modulus v = sqrt((-2)^2+4^2)=sqrt20=2sqrt5

u.v = 2 x -2 + (5 x 4) = 16

so 16=2sqrt5sqrt29cos(theta)

cos(theta)=8/(sqrt29sqrt5)

theta = cos^(-1) of (8/sqrt29sqrt5)
0
X
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

If you're planning on going to uni this year, would any of these financial reasons stop you?

Not being able to work now to save up for uni (85)
14.07%
Reduced household income due to coronavirus means I can't afford to go (50)
8.28%
Lack of part-time jobs to support me while I'm at uni (75)
12.42%
Lack of graduate job prospects when I finish uni (67)
11.09%
Other reasons are stopping me going (79)
13.08%
Nothing is stopping me going (248)
41.06%

Watched Threads

View All