VCE Methods Question Thread!

[cosine]

Describe the transformations from y=1/x^2 to y= 8/(2x+1)^2 -1

Would it still be correct if I actually simplify out the denominator by taking a common factor of 2, then squaring it and dividing by 8, leaving 2/(x+1/2)^2 -1 and describe the transformations from there ?

I see this as more suitable, it's like saying translation of 2 units up, then translation 3 units down. Whereas you could just say move 1 down.. Is it the same concept ?

Cheers!

[cosine]

Can someone help with this please? Thanks (attached)

[Redoxify]

given that the curved surface area of a cone of height h and radius r is pi x r x root(r^2 + h^2),
show that the curved surface area can be expressed as A=pi x root(r^6+144)all over r

[Redoxify]

find the dA/dr
A= pi root(r^6 + 144)/r

[knightrider]

So you probably introduced the log a step too early to see the second solution.








compare with the equivalent working










which reduces to what the calculator got. In the negative case, you leave it all inside the log, and in the positive case, there's no annoying minus sign so you can bring the 1/4 out the front of the log.


HOWEVER, the first solution from CAS is a bit fishy imo,



, like a square root, will never be negative, because even roots only return positive powers or are undefined if their argument is negative.

is bound to be undefined. I dont even thing this second answer is valid.

Thankyou so much silverpixeli 

[cosine]

find the dA/dr
A= pi root(r^6 + 144)/r

Let









And then just simplify from there, LaTex would be too tedious here to do so

[Redoxify]

can someone help with the following
find the derivative of ln(e^2x + Ln(x))

[Redoxify]

evaluate
25^log5(3)

[cosine]

can someone help with the following
find the derivative of ln(e^2x + Ln(x))

Let

[Redoxify]

Let

your answer isn't one of the options :\

[cosine]

your answer isn't one of the options :\

Simplify this, again, this is AN, LaTex would be too tedious and difficult to type it, but the method is correct. There is always more than one way to express the answer, so play around with it and try to suit it with an available answer.

[cosine]

When it says to sketch one full cycle, after the transformations do we still restrict to 0 and the period?
For the example attached, question says sketch one full period, but their answer starts at pi/3 and ends at 7pi/3 which i understand why, but do we not have to restrict it to 0,2pi?

[Redoxify]

finding the derivative of
(x^2 + 2x +1)^-2

i got the answer to be
-4x-4(x^2 + 2x +1)^-3
in the book it is something with power -5

[knightrider]

How would you solve this equation for y ?

[cosine]

How would you solve this equation for y ?

This has complex solutions, it shouldn't be in your methods book.