Curve Sketching (1 Viewer)

[angeleyez]

I need help with curve sketching. The stuff where you are given the first derivative and you have to sketch the original function! If anyone has any idea, please reply ASAP

 

[Nelly]

Aiigh, this is EXTREMELY hard to describe in words. but here goes:

BTW, this is a 4U topic, so if u just do 3U, you dont have to worry.

f'(x) = whatever
graph f(x).

Now, each point on the graph f'(x) is the gradient of f(x).

So when f'(x) = 0, then f(x) is having a turning point.

If f'(x) is having a turning point, then f(x) has a point of inflexion.

You don't have to worry about where it crosses the y-axis or whatever, because you dont know f(x), because if you integrate f'(x) you get a + C, so you never know how high or low it might be.

I hope that helped, and good luck in 2 weeks

 

[Jellymonsta]

i dont know if it is in the syllabus but i was given a 4 mk simple version of that in my 3u trials.
the teacher said it was a tough exam, so i don't know if it would actually show up in the hsc

 

[mastermind]

angeleyez -

i dont know about actually being in the syllabus, BUT this type of question was asked in 2000 2U maths paper. So even if you don't do 4U, be prepared for possibly another one this year...

 

[Lazarus]

Yeah, uhm, it's a 2u topic.

The types of curves that you'll be asked to graph will depend on the level of maths you do (i.e. no cusps in 2u or 3u) but curve-sketching is still a part of the syllabus.

 

[Jinxd]

I did a question like that in the trials for 2U. The question was later removed because there were 2 answers and I never found out whether I was right. BUT what I did was find the integral of the gradient function and sub in a known point to find the constant.

I'll post later on cos I have math tutoring in an hour.

 

[underthesun]

actually, you should take a look at the 4u graphs. Just ask someone for it, and it'll help you a lot. Mind you tho, not to go to the other topics other than graph

 

[Dumbarse]

i did one of these questions it was bullcrap, and hwat the hell is a cusp, how do u know when the graph has a cusp and how do u draw the cusp??

 

[BlackJack]

Think a cusp is some point formed by two curves touching ... the middle bit of this } would probably be one...

 

[Dumbarse]

thanx