Dispute over solution: Rates of Change. (2 Viewers)

[hayabusaboston]

what im interested to know is how your teacher even got 10.5?

Since A=pi.r^2, and V=1/3 times pi.r^2h, teacher put A into V and made V=1/3Ah, and went from there.

 

[asianese]

The thing is V is a function of 2 variables...lol

 

[hayabusaboston]

The thing is V is a function of 2 variables...lol

Wot, so this is the argument I should use to explain why you cant just sub in A into V?

So in general, what arguments should I use to explain why 10.5 is wrong?

 

[braintic]

Wot, so this is the argument I should use to explain why you cant just sub in A into V?

So in general, what arguments should I use to explain why 10.5 is wrong?

Tell your teacher that when she is differentiating, she is treating h as a constant, when in fact it varies with time.
Also tell your teacher that she shouldn't be teaching Extension maths.

 

[hayabusaboston]

Tell your teacher that when she is differentiating, she is treating h as a constant, when in fact it varies with time.
Also tell your teacher that she shouldn't be teaching Extension maths.

Yea she got 70 as her mark in HSC for ext 1, and idk about 2u. She didnt even do extension 2 haha.

But hey she's good at explaining things, im just not sure if she knows what she's doing sometimes -__-

 

[Carrotsticks]

Teachers make mistakes like anybody else, but it's another thing for to completely deny a correct solution for whatever reason (from what I've seen so far, it's unfortunately pride...).

But that's not to say all teachers are like that of course, but it's unfortunate that it happens sometimes.

 

[iBibah]

Tell your teacher that when she is differentiating, she is treating h as a constant, when in fact it varies with time.
Also tell your teacher that she shouldn't be teaching Extension maths.

As much as this feels like it needs to be said, probably not a good idea lol

Teachers make mistakes like anybody else, but it's another thing for to completely deny a correct solution for whatever reason (from what I've seen so far, it's unfortunately pride...).

But that's not to say all teachers are like that of course, but it's unfortunate that it happens sometimes.

Too many teachers have this....way too many.....

 

[anomalousdecay]

Too many teachers have this....way too many.....

Except for my Maths teacher. He gave us our tests back and said "If I have any mistakes, please tell me."

Of course, my teacher is too pro to make a mistake anyways. And most of our tests are from external sources, such as HSC past papers and trials.

 

[iBibah]

Except for my Maths teacher. He gave us our tests back and said "If I have any mistakes, please tell me."

Of course, my teacher is too pro to make a mistake anyways. And most of our tests are from external sources, such as HSC past papers and trials.

That's why I said 'most', because some teachers are great when it comes to mistakes, some even offer little rewards like chocolates for pointing them out.

 

[seanieg89]

Teachers make mistakes like anybody else, but it's another thing for to completely deny a correct solution for whatever reason (from what I've seen so far, it's unfortunately pride...).

But that's not to say all teachers are like that of course, but it's unfortunate that it happens sometimes.

+1. The number of stubborn and prideful high school maths teachers I have met is ridiculous.

One major thing that makes science and in particular mathematics such an objective and pure intellectual pursuit is that there is no authority when it comes to establishing facts. One persons opinion is no more valid than anothers without proof, or at the very least some evidence.

People who try to argue by authority rather than carefully considering their critics questions are the worst possible thing for progress, especially when it is a teacher whose actions are creating an environment which is not open to "silly questions". Silly questions are often the ones we learn the most from.

 

[asianese]

Yea she got 70 as her mark in HSC for ext 1, and idk about 2u. She didnt even do extension 2 haha.

But hey she's good at explaining things, im just not sure if she knows what she's doing sometimes -__-

Did she do a Bachelor's of Science/Arts/Mathematics??

Or is she just like a student teacher?