Specialist 1/2 Question Thread!

[pans]

Can someone please explain CHAPTER 4A Q1E.

[Ruchir]

Can someone please explain CHAPTER 4A Q1E.

It is saying that tn+1 which is the next term is equal to twice the nth term term or current term (tn) adding the previous term tn-1
In context with the question the current term is   t2 = 3 and the previous term is t1=1

There fore t3 = 2*3(or t2) + 1(or tn-1)
Therefore t3 = 7
The follows on with the next term being t4 , current term being t3 and previous term being t2.

[pans]

omg DUDE THANK YOU I GET IT NOW

[pans]

Can someone please explain 4A Q7C.

[fun_jirachi]

You should use the recurrence relation found in part b).

Given that \(t_0 = 94.3s\), you need to be finding \(t_8\) using the relation as this indicates 8 weekly 4% reductions from her time.

[pans]

pls explain 4C Q12

[pans]

You should use the recurrence relation found in part b).

Given that \(t_0 = 94.3s\), you need to be finding \(t_8\) using the relation as this indicates 8 weekly 4% reductions from her time.

Thank you!

[fun_jirachi]

pls explain 4C Q12

What exactly do you not understand? Is it perhaps setting up the arithmetic sequence/arithmetic sequences altogether (or something completely different)? Your question is quite vague - we ideally want to explain arithmetic sequences (and other sequences too!) so you understand them completely and can apply said explanations to every form of question

[Cate_m]

Hey I've got a Spesh sac next week and I would really appreciate some help on this question

Express the following as a partial fraction

[fun_jirachi]

Hi there!

I'd really love to help, but without further context it's impossible to answer this question! Is there any other information that you could give us?

[Cate_m]

Yep, this is the summary in the textbook of what they want done

[fun_jirachi]

I'm sorry, I didn't read the text above the question! My bad

Firstly, note that \((x-2)(x^2-4) = x^3-2x^2-4x+8 = x^3-2x^2-3x+9 - (x+1)\).

Hence, we can do the following:
.

We can then apply the method of partial fractions to the remaining fractional part.



Hence, \(\frac{x^3-2x^2-3x+9}{x^2-4} = x - 2 + \frac{3}{4(x-2)} + \frac{1}{4(x+2)}\). Try this with a few other examples and see how you go

[Cate_m]

Hey, it's me again. Could somebody please explain 11b

[fun_jirachi]

You're given that \(d = k\sqrt{h}\) for some constant \(k\). You can find said constant by substituting \(d=4.8, \ h = 1.8\). Note also that height is in metres while distance is in kilometres - so you to make it easier, you can make the necessary conversion. You don't have to, but it just means you have to remember your units really well. Also, it is implied that you should assume the person in the question is standing up at sea level.

Thus, we have that \(k = \frac{4800}{\sqrt{1.8}} \implies \ d = \frac{4800\sqrt{h}}{\sqrt{1.8}}\).

The first question basically tells you that at the top of the tower, they can see \(\frac{4800\sqrt{5.8}}{\sqrt{1.8}} m\) into the distance. This is implied to be the same distance from the person to the top of the mast. A diagram drawn with this information should look something like the one below.

Spoiler

From here, you can use Pythagoras' Theorem to find the distance from the yacht to the tower (which is exactly on the coast).

Totally understand your confusion as there are a lot of assumptions you have to make - not the best question in the world imo

Hope this helps

[Cate_m]

Thank you, you're a life saver