VCE Methods Question Thread!

[snowisawesome]

Yeah.

Why wouldn't you be?

What do you mean?
Is it actually correct or not though?

[DBA-144]

What do you mean?
Is it actually correct or not though?

Yes it is correct.

[snowisawesome]

Yes it is correct.

Thanks
-y = 2*((x+4)/3-4)^(1/2)+3.5
Do you know how you would make y the subject of the formula?

Also, do you know how to make y the subject of
(3y-4)^2=(3/(x-6))
Thanks again

[Yertle the Turtle]

Thanks
-y = 2*((x+4)/3-4)^(1/2)+3.5
Do you know how you would make y the subject of the formula?

Also, do you know how to make y the subject of
(3y-4)^2=(3/(x-6))
Thanks again

For the first one just multiply both sides by -1, so that it becomes y=-2((x+4)/3-4)^(1/2)-3.5

For the second you take the square root of both sides, add 4 to both sides and then divide by 3. It is just basic Order of Operations.
y=(((3/(x-6))^1/2)+4)/3

[snowisawesome]

For the first one just multiply both sides by -1, so that it becomes y=-2((x+4)/3-4)^(1/2)-3.5

For the second you take the square root of both sides, add 4 to both sides and then divide by 3. It is just basic Order of Operations.
y=(((3/(x-6))^1/2)+4)/3

For my second question, would you take the positive square root of both sides, or the positive and negative square root of both sides

[Yertle the Turtle]

For my second question, would you take the positive square root of both sides, or the positive and negative square root of both sides

Positive and negative. I just don't know how to do the 'plus or minus' sign on here. Sorry for the confusion.

[snowisawesome]

Positive and negative. I just don't know how to do the 'plus or minus' sign on here. Sorry for the confusion.

Thanks
Do you know how you would sketch the graph of y = 0.5cos(x) from the graph of y = cos(x)
Thanks

[Yertle the Turtle]

Thanks
Do you know how you would sketch the graph of y = 0.5cos(x) from the graph of y = cos(x)
Thanks

The amplitude of the graph is 1/2 instead of 1. Therefore the graph has the same intercepts, but its peaks are half the height of the normal cos graph.

[skrt skrt]

A cubic function has the equation f(x)=x^3-6x^2+12x+B , where B is a non-zero constant. If f(x) can be expressed in the form: (x-A)^3-4 , find the values of A and B.

Thanks in advance

[Sine]

A cubic function has the equation f(x)=x^3-6x^2+12x+B , where B is a non-zero constant. If f(x) can be expressed in the form: (x-A)^3-4 , find the values of A and B.

Thanks in advance

what part of the question is troubling you? Presenting anything that you have done or at least tried will allow for other users to make their best attempt in helping you

[skrt skrt]

I've tried expanding the turning point form into x^3-3Ax^2+3A^2x+A^3-4 and I keep getting A=2 and B=4 which when I put into demos is not the same graph.

Am I going in the right direction with this question?

Thankss

[Shadowxo]

I've tried expanding the turning point form into x^3-3Ax^2+3A^2x+A^3-4 and I keep getting A=2 and B=4 which when I put into demos is not the same graph.

Am I going in the right direction with this question?

Thankss

Your thinking is right, you just made a mistake, it should be

The coefficient of A³ is -1, not +1. You have the right value for A but you'd get a different answer for B,
-A³-4=B
-8-4=B
B=-12

[snowisawesome]

How much work is needed to get 35 raw in methods for an average maths student?
I'm sort of struggling with transformations at the moment, are there any ways to better understand transformations?
Thanks
Also, can someone please explain how to find the rule for the image of the graph of y = -x^2 under the following:
reflection in the y-axis
dilation of factor 2 from the y-axis
translation 4 units in the positive direction of the x-axis and 6 units in the positive direction of the y-axis
Thanks

[Sine]

How much work is needed to get 35 raw in methods for an average maths student?
I'm sort of struggling with transformations at the moment, are there any ways to better understand transformations?
Thanks
Also, can someone please explain how to find the rule for the image of the graph of y = -x^2 under the following:
reflection in the y-axis
dilation of factor 2 from the y-axis
translation 4 units in the positive direction of the x-axis and 6 units in the positive direction of the y-axis
Thanks

work required will be different for everyone

With transformations try to understand how the graph is chaing --> i.e. is the x values being changed or y, has it been stretched/reflected etc

y = -x^2
reflection in the y-axis
y=-(-x)^2 = -x^2
dilation of factor 2 from the y-axis
y=-(x/2)^2 = -x^2/4
translation 4 units in the positive direction of the x-axis and 6 units in the positive direction of the y-axis
y=-(x-4)^2/4 + 6

[snowisawesome]

work required will be different for everyone

With transformations try to understand how the graph is chaing --> i.e. is the x values being changed or y, has it been stretched/reflected etc

y = -x^2
reflection in the y-axis
y=-(-x)^2 = -x^2
dilation of factor 2 from the y-axis
y=-(x/2)^2 = -x^2/4
translation 4 units in the positive direction of the x-axis and 6 units in the positive direction of the y-axis
y=-(x-4)^2/4 + 6

When you said the work required will be different for everyone, is there still like a number of hours that we should do methods each week, and number of practise exams for an average student to get 35 raw?