Prelim 2016 Maths Help Thread (2 Viewers)

[Green Yoda]

What about the others

Also leehuan could you please show me the working to the rates of change question

They are similar..use the same technique
I kinda use another technique but its the same outcome. There are like 5-6 methods to do rational inequalities.

 

[eyeseeyou]

They are similar..use the same technique
I kinda use another technique but its the same outcome. There are like 5-6 methods to do rational inequalities.

I tried all of them and for some reason I couldn't do them

 

[leehuan]

What about the others

Also leehuan could you please show me the working to the rates of change question

When you post questions that are a repeat of the same method that reduces my botheredness to do them

So I'll only do the last one.

 

[eyeseeyou]

iirc in one of the examples I posted above, there involves a quadratic

 

[leehuan]

-1, -1/3, 2, less



Line 4 is achieved with help of expanding AND factorising by grouping in pairs

 

[eyeseeyou]

-1, -1/3, 2, less



Line 4 is achieved with help of expanding AND factorising by grouping in pairs

What do you mean by -1,-1/3, 2, less?

 

[leehuan]

What do you mean by -1,-1/3, 2, less?

That's how I do it.

At your level just learn to draw a graph of the cubic y=(t+1)(3t+1)(t-2)

 

[eyeseeyou]

Also for an esy example like this 1/(x-1) is greater than or equal to 2 apparently the answer is 1 is less than x is less than or equal to 3/2

why is this? I'm so confused

 

[eyeseeyou]

BTW leehuan could you do the solution to my rate of change question

Thanks

 

[leehuan]

Also for an esy example like this 1/(x-1) is greater than or equal to 2 apparently the answer is 1 is less than x is less than or equal to 3/2

why is this? I'm so confused

Use the exact same process???

1/(x-1) <= 2

(x-1) <= 2(x-1)^2

x-1 <= 2x^2-4x+2

0 <= 2x^2 - 5x + 3

(x-1)(2x-3) >= 0

x<1, x>=3/2

(Obviously x can't equal to 1 if you look at the start of the question)

 

[parad0xica]

What do you mean by -1,-1/3, 2, less?

I think he's writing down his thought process.

-1, -1/3, 2 being the roots and "less" meaning look for values where the graph is "less" than (or equal to) 0

 

[eyeseeyou]

Use the exact same process???

1/(x-1) <= 2

(x-1) <= 2(x-1)^2

x-1 <= 2x^2-4x+2

0 <= 2x^2 - 5x + 3

(x-1)(2x-3) >= 0

x<1, x>=3/2

(Obviously x can't equal to 1 if you look at the start of the question)

Oh holy shit I am blind

Once again thanks leehuan. I don't know how I could've done it without you

 

[eyeseeyou]

Will be asking motion questions tonight at approximately 9pm

Will there be someone available to help me (leehuan/Integrand/David)?

 

[Paradoxica]

Will be asking motion questions tonight at approximately 9pm

Will there be someone available to help me (leehuan/Integrand/David)?

Hi

 

[eyeseeyou]

leehuan/Integrand Need your help urgently

 

[Shuuya]

eyeseeyou has come, as promised! Post up your questions

 

[si2136]

Will be asking motion questions tonight at approximately 9pm

Will there be someone available to help me (leehuan/Integrand/David)?

Doing motion already

If you post the questions, that would be helpful, thanks

 

[eyeseeyou]

Doing motion already

If you post the questions, that would be helpful, thanks

Okay here:

I just can't seem to get the jist of these questions

1.The velocity of a particle moving in a straight line is given by v=2t-4 ms. Initially the particle is 3m to the right of the origin O
a)find the displacement of the particle, x metres, at t second
b)Sketch the graph of x against t
c)Find the displacement at t=3
d)Find the distance travelled during the time interval 0≤t≤3
e)Find the acceleration of the particle at t=2

2. If v=t+lt-2l m/s, sketch the graph of v against t for 0≤t≤6, and hence find the distance covered during this time interval

3. A particle is moving in a straight line. It starts from a fixed point O on the line and at time t second its velocity v m/s is given by v=2cost
a. Find the first two times when the particle is at rest
b. find the distance travelled by the particle between these two lines
c. Find the acceleration particle when it is at rest

4. A particle moves in a straight line so that at any time t≥0 its velocity is given by v=1/(1+t)
a. if its distance from a fixed point O on the line is x, show that x=In(1+t), given that x=0 when t=0
b. Show that the particle is moving away from O as t increase
c. Find acceleration when t=0

5. An object falling from rest in air is suspended to an acceleration x (with 2 dots on top of x)=g-(v/k dash) where g and k are constants and v is the velocity and time t
a. Show that v=gk (1-(e^-(t/k)))
b. What is the greatest speed obtained?
c. What is the greatest distance travelled in the time t=k In 4

 

[eyeseeyou]

Okay here:

I just can't seem to get the jist of these questions

1.The velocity of a particle moving in a straight line is given by v=2t-4 ms. Initially the particle is 3m to the right of the origin O
a)find the displacement of the particle, x metres, at t second
b)Sketch the graph of x against t
c)Find the displacement at t=3
d)Find the distance travelled during the time interval 0≤t≤3
e)Find the acceleration of the particle at t=2

2. If v=t+lt-2l m/s, sketch the graph of v against t for 0≤t≤6, and hence find the distance covered during this time interval

3. A particle is moving in a straight line. It starts from a fixed point O on the line and at time t second its velocity v m/s is given by v=2cost
a. Find the first two times when the particle is at rest
b. find the distance travelled by the particle between these two lines
c. Find the acceleration particle when it is at rest

4. A particle moves in a straight line so that at any time t≥0 its velocity is given by v=1/(1+t)
a. if its distance from a fixed point O on the line is x, show that x=In(1+t), given that x=0 when t=0
b. Show that the particle is moving away from O as t increase
c. Find acceleration when t=0

5. An object falling from rest in air is suspended to an acceleration x (with 2 dots on top of x)=g-(v/k dash) where g and k are constants and v is the velocity and time t
a. Show that v=gk (1-(e^-(t/k)))
b. What is the greatest speed obtained?
c. What is the greatest distance travelled in the time t=k In 4

Had to use microsoft word for that lol not Latex

 

[eyeseeyou]

Okay here:

I just can't seem to get the jist of these questions

1.The velocity of a particle moving in a straight line is given by v=2t-4 ms. Initially the particle is 3m to the right of the origin O
a)find the displacement of the particle, x metres, at t second
b)Sketch the graph of x against t
c)Find the displacement at t=3
d)Find the distance travelled during the time interval 0≤t≤3
e)Find the acceleration of the particle at t=2

2. If v=t+lt-2l m/s, sketch the graph of v against t for 0≤t≤6, and hence find the distance covered during this time interval

3. A particle is moving in a straight line. It starts from a fixed point O on the line and at time t second its velocity v m/s is given by v=2cost
a. Find the first two times when the particle is at rest
b. find the distance travelled by the particle between these two lines
c. Find the acceleration particle when it is at rest

4. A particle moves in a straight line so that at any time t≥0 its velocity is given by v=1/(1+t)
a. if its distance from a fixed point O on the line is x, show that x=In(1+t), given that x=0 when t=0
b. Show that the particle is moving away from O as t increase
c. Find acceleration when t=0

5. An object falling from rest in air is suspended to an acceleration x (with 2 dots on top of x)=g-(v/k dash) where g and k are constants and v is the velocity and time t
a. Show that v=gk (1-(e^-(t/k)))
b. What is the greatest speed obtained?
c. What is the greatest distance travelled in the time t=k In 4

Don't think this was the right place to post this since motion is HSC not prelim