VCE Methods Question Thread!

[Zidane]

hey guys    so im stuck with this question, i kind of know how to do it but unsure.



Thanks guys 

[Jenny_2108]

hey guys    so im stuck with this question, i kind of know how to do it but unsure.



Thanks guys 

My teacher hasnt taught us yet. I've just read this chapter in the textbook so I know how to do it by CAS but I dont know how to do by hand though.
Maybe someone else may help you to do by hand



Pr(X<23) = 0.57926

Pr(X<k) = 0.57926 * 0.32= 0.18536

Put in CAS for inverse normal, you get k=17.5176

Check your ans, possibly I do wrong 

[Zidane]

i did all of that i didn't put that value invNorm(0.18536,0,1) in calculator ..... sigh 
But thanks for that, and yeah you are correct!!! 

[Jenny_2108]

i did all of that i didn't put that value invNorm(0.18536,0,1) in calculator ..... sigh 
But thanks for that, and yeah you are correct!!! 

you put invNorm(0.18536, 22,5), not invNorm(0.18536,0,1)

Its not a standard normal distribution

[Zidane]

i did all of that i didn't put that value invNorm(0.18536,0,1) in calculator ..... sigh 
But thanks for that, and yeah you are correct!!! 

you put invNorm(0.18536, 22,5), not invNorm(0.18536,0,1)

Its not a standard normal distribution

sprry my bad

[nangwo]

I was wondering with the process of graphing the derivative of a graph, is the shape something you should just know off by heart? I know graphs like x^4 become x^3 to x^2 and then linear, but what about graphs with a rational power?

About graph with a rational power, you find derivative then graph it.
There are some basic shapes with rational power graphs. I just remember it
I doubt they have this kind of question in exam 1

mmk thanks, i came across one in a trial exam (not vcaa though), i think the derived graph was x^-(1/3)

[TrueTears]

I was wondering with the process of graphing the derivative of a graph, is the shape something you should just know off by heart? I know graphs like x^4 become x^3 to x^2 and then linear, but what about graphs with a rational power?

About graph with a rational power, you find derivative then graph it.
There are some basic shapes with rational power graphs. I just remember it
I doubt they have this kind of question in exam 1

mmk thanks, i came across one in a trial exam (not vcaa though), i think the derived graph was x^-(1/3)

You should probably just take tangents at specific points and sketch the graph rather than memorising the general shape.

[nisha]

Simple probability question, yet I've forgotten how to do it:

1. One out if three people read the Bugle Newspaper, while one out of five read the Headline. if four people are sampled, what is the probability that:
(a)one of them reads the Headline?
(b)atlas three of the read the Bugle?

[FlorianK]

Simple probability question, yet I've forgotten how to do it:

1. One out if three people read the Bugle Newspaper, while one out of five read the Headline. if four people are sampled, what is the probability that:
(a)one of them reads the Headline?
(b)atlas [at least ?] three of the read the Bugle?

Not sure if I understand the question correctly but:
a) 4*(0.2)*(0.³=0.4096
b) 4*(1/3)³*(2/3)+(1/3)⁴=1/9

[nisha]

Simple probability question, yet I've forgotten how to do it:

1. One out if three people read the Bugle Newspaper, while one out of five read the Headline. if four people are sampled, what is the probability that:
(a)one of them reads the Headline?
(b)atlas [at least ?] three of the read the Bugle?

Not sure if I understand the question correctly but:
a) 4*(0.2)*(0.³=0.4096
b) 4*(1/3)³*(2/3)+(1/3)⁴=1/9

Thankyou

[FlorianK]

Simple probability question, yet I've forgotten how to do it:

1. One out if three people read the Bugle Newspaper, while one out of five read the Headline. if four people are sampled, what is the probability that:
(a)one of them reads the Headline?
(b)atlas [at least ?] three of the read the Bugle?

Not sure if I understand the question correctly but:
a) 4*(0.2)*(0.³=0.4096
b) 4*(1/3)³*(2/3)+(1/3)⁴=1/9

Thankyou

No problem. So it was correct, right?

It's just binominal distribution. The 4 is there, because ⁿC₁ = n

[Jenny_2108]

I was wondering with the process of graphing the derivative of a graph, is the shape something you should just know off by heart? I know graphs like x^4 become x^3 to x^2 and then linear, but what about graphs with a rational power?

About graph with a rational power, you find derivative then graph it.
There are some basic shapes with rational power graphs. I just remember it
I doubt they have this kind of question in exam 1

mmk thanks, i came across one in a trial exam (not vcaa though), i think the derived graph was x^-(1/3)

You should probably just take tangents at specific points and sketch the graph rather than memorising the general shape.

@ True Tears: I mean at first you need to know the basic shape of original graph.
Then you can draw the derivative graph based on the original one

@ nangwo: Anyway, guess what??? I'm reading Derrick Ha's maths notes and he has a very interesting way to draw the graph of rational power.
I can't wait to share with you

Well, he wrote that: to sketch the graph there are 3 steps
1. Sketch
2. Sketch y=x
3. Reflect the first graph along the line y=x

However, this method is only used when n is positive 
In your question, n is negative so you can't apply this method

I think you can re-write
And this graph has similar shape as the rectangular hyperbola graph 

[FlorianK]

What is the general solution for asymptotes of tan(ax)?

[Conic]

What is the general solution for asymptotes of tan(ax)?

x=((2kπ+1)*π)/(2*a)
π=pi

[brightsky]

What is the general solution for asymptotes of tan(ax)?

another way to think about it:

you know asymptotes of tan(x) can be written in the general form pi/2 + n*pi, where n is an integer.
tan(ax) involves a dilation of 1/a from the y-axis, which stretches the x-values. so asymptotes become 1/a(pi/2 + n*pi).
or you could simply let whatever is in the brackets (i.e. ax) = pi/2 + n*pi and solve for x.