Secondary Maths questions, give me your maths questions

[mdc]

Yes, I'm still a bit confused as to how I actually sketch the graph without knowing the value of x, A, or P.

If you're not given any of those values, nor any other constraints, you can sketch it for a couple of different values of P.

For example, assume P = 4x (i.e. it's a square), then sketch.
Next assume P = 8x or similar, and sketch.

Do about 3-4 of these on the same graph, and voila.

edit: Or, as SJ suggests you can do it in "general" form, which is probably easier if you've covered it in class.

 

[treefingers]

We haven't covered this in class yet, so I'm still a little bit confused, but thanks heaps for the help.

I'm not a dummy at maths I'll let you know when I get it

btw this is only year 10 stuff.

 

[treefingers]

Therefore intercepts on the horizontal axis at L = 0 and L = P/2.

Therefore the turning point at (P/4, P^2/16)

You could draw it like that.

This is definitely the right answer I was looking for, thanks

 

[Moonwatcher]

need to show that a bounded sequence has a convergent subsequence that converges to its limes superior.

and that the limes superior is the greatest limit possible.

there is nothing on the net along these lines. so help would be appreciated.

 

[mdc]

need to show that a bounded sequence has a convergent subsequence that converges to its limes superior.

and that the limes superior is the greatest limit possible.

there is nothing on the net along these lines. so help would be appreciated.

Look up the Bolzano-Weierstrass theorem in your notes/text for the first part.

For the second part it's probably easiest to do it by contradiction, just using the definitions of bounded and lim sup.

 

[Moonwatcher]

Think i've got it though havent written it down yet,

by the definition of the supremum and the order limit theorem all convergent subsequences converge to a value less than or equal to limes supremum.

and there is a subsequence that converges to limes sup , because the sequence that leads to the definition of the limes sup converges bringing with it an infinite number of members of the parent sequence. ( i can visualise this one in my head, but really should be written down)

 

[Moonwatcher]

Look up the Bolzano-Weierstrass theorem in your notes/text for the first part.

For the second part it's probably easiest to do it by contradiction, just using the definitions of bounded and lim sup.

Actually if i wrote down the proof it would act as a proof of Balzano- Weierstrass

 

[Schache It Off]

9000 + 1 = ????

???? Must be answered in a Dragonball Z term.

 

[treefingers]

9000 + 1 = ????

???? Must be answered in a dragonball z term.

its over nine thousaand!

 

[BILC]

Find algebraically the coordinates of the intersestion points of

y= 1/2x and 2x+3y = 12. Let this point be A

Y=-2x and 2x+3y = 12. Let this point be B

Im guessing that you would just have to get the coordinates out of those 2 points, but how do you tell x from y?

 

[SJ]

Find algebraically the coordinates of the intersestion points of

y= 1/2x and 2x+3y = 12. Let this point be A

Y=-2x and 2x+3y = 12. Let this point be B

Im guessing that you would just have to get the coordinates out of those 2 points, but how do you tell x from y?

A:

y = (1/2)x (I assume you mean this and not y = 1/(2x))

2x + 3y = 12
2x + 3(1/2)x = 12
2x + (3/2)x = 12
(7/2)x = 12
x = 24/7

y = (1/2)x = (1/2)(24/7) = 12/7

Therefore point A is at (24/7, 12/7) using the assumption above.

See if you can do point B.

 

[treefingers]

Find the area of the largest square which fits inside the triangle. I'm really not sure where to start with this one.

 

[mdc]

Find the area of the largest square which fits inside the triangle. I'm really not sure where to start with this one.

Whoever drew that diagram isn't doing you any favours, but otherwise it's a nice qn.

Call the length of the line connecting the two non-base sides (ie 20 & 13) W. See if you can find an expression for W in terms of some other variable.

 

[MightyFighting]

Find the area of the largest square which fits inside the triangle. I'm really not sure where to start with this one.

You can split the big triangle into three little triangles and a square. You then have an expression for the sides of the three triangles and square in terms of the sides of the big triangle.

 

[BILC]

On the one set of axes, sketch the graphs of the following relations. Clearly label x and y intercepts and label the origin O

2x+3y=12
y = -2x
Y = 1/2x

????????

 

[SJ]

On the one set of axes, sketch the graphs of the following relations. Clearly label x and y intercepts and label the origin O

2x+3y=12
y = -2x
Y = 1/2x

????????

I don't want to 'do it' for you again this time.

Surely you have some idea. What are you stuck with specifically? Can you do the second and third equations at least?

 

[BILC]

I don't want to 'do it' for you again this time.

Surely you have some idea. What are you stuck with specifically? Can you do the second and third equations at least?

Yeah, yeah, i just cant put them together, im not sure how to graph it

I cant seem to get the first one, when i get to 1 on the x axis it comes up as pie and i dunno what the hell to do

Oh and thanks for help on those other ones, i get it now

 

[SJ]

If I was you I'd get the first equation in terms of y, before graphing.

2x + 3y = 12
3y = 12 - 2x
y = 4 - 2x/3

So a linear equation with y-intercept of 4 (0,4) and a gradient of -2/3.

 

[magic_johnson!]

The basic equation for a linear equation is y=mx + c
So, y=1/2x

shows that m=1/2. You can get this far yes?

There is no c, which may seem odd, but it means that c is just equal to 0. Therefor the y intercept is 0.

The gradient (or m) is written as rise over run. in this equation, m=1/2, which means for every 1 unit it goes up the graph it goes 2 units across, so if the line passes through (0,0) (the y intercept is 0 remember), when the line is at 1 on the y axis, x should be 2. so it passes through point (1,2). next point would be (2, 4) ect.

Graphs with a positive gradient go up diagonally to the right.
Graphs with a negative gradiant go down diagonally to the right.

 

[jinny1]

Help please.

The polynomial P(x) = x^3 + ax^2 + bx +56 is exactly divisible by x-2 and when divided by x+5 has a remainder of -84.

Find the values of a and b

THanks

 

[mdc]

Help please.

The polynomial P(x) = x^3 + ax^2 + bx +56 is exactly divisible by x-2 and when divided by x+5 has a remainder of -84.

Find the values of a and b

THanks

Look up "Polynomial remainder theorem" in your text book. You should get 2 simultaneous equations to solve.

 

[jinny1]

Look up "Polynomial remainder theorem" in your text book. You should get 2 simultaneous equations to solve.

could you just show me the working out?

 

[mdc]

could you just show me the working out?

Of course not, what would be the point?

Attempt the question, and if you get stuck post your working here.

 

[jinny1]

Of course not, what would be the point?

Attempt the question, and if you get stuck post your working here.

i dont get why you need simultaneous equations to solve... there is only one equation here..

how about you show me the first few ste[s and ill work out the rest...

 

[mdc]

i dont get why you need simultaneous equations to solve... there is only one equation here..

Because you have two unknowns (a and b). You also have two pieces of information, the first is "exactly divisible by x-2" and the second is "when divided by x+5 has a remainder of -84".

Like I said, look up the Polynomial Remainder Theorem in your text, and you'll see that each of these pieces of information will give you an equation.