VCE Methods Question Thread!

[b^3]

Its just solving them simultaneously, but you'll end up with the result in terms of .

HINT: Try to use a substitution method or elimination method before looking at this spoiler

[darklight]

I understand the simultaneous parts, but not the exclusions.

What can't m be 4? And according to the book, it can't be 0 either?

[507]

If , you would be dividing by zero.

If , which the author may not consider to be a linear function.

[BubbleWrapMan]

Excluding m = 0 is incorrect

[Jaswinder]

if m was zero wouldn't it give an unique solution rather than infinite or no solution since its just a straight horizontal line?

[abcdqdxD]

The only other way I can think of is that if you know that you have three x intercepts for a quartic, you also know that if the graph starts from the top then it will leave towards the top too (or starts from the bottom then leaves from the bottom too), as with the other even power graphs.

x(x-1)^2(x+3)(x+5) comes from bottom and leaves from top, how do I know if the graph will leave the opposite direction it came from?

EDIT: sorry realised its not a quartic. How come it looks nothing like a cubic graph?

[Professor Polonsky]

It actually does have the general shape of an odd-power polynomial, if you zoom out enough.

[abcdqdxD]

but how do I know how to graph it when my graph is zoomed in?

[b^3]

It actually does have the general shape of an odd-power polynomial, if you zoom out enough.

As Polonius has said https://www.desmos.com/calculator/fpjvrbycqx

But yeh, basically polynomials of powers 3, 5, 7 e.t.c. (odd numbered) may look similar, except there can be more intercepts in that latter than the former. But for these functions, if they enter from the bottom, they'll leave through the top and vice versa. Compared to even function graphs that will enter and leave from either the top or the bottom.

but how do I know how to graph it when my graph is zoomed in?

You zoom out/look at it from further out and scale the axis differently to each other, as in the link above.

[jimmy22]

Hey,
How do you find the area of an irregular quadrilateral?

Question 3, part e, Extended response of chapter 2 review set, essentials.

thanks

[BubbleWrapMan]

I'd split it into two triangles, find AC, and use Heron's formula for both

[jimmy22]

I'd split it into two triangles, find AC, and use Heron's formula for both

Thanks, but not really sure what Heron's formula is. Are you expected to know this in methods?

[BubbleWrapMan]

http://en.wikipedia.org/wiki/Heron's_formula

Don't need to know it, but it's convenient.

You could alternatively find the angles ABC and ADC, and then use the formula 1/2 bc sin(A) (that's one you do need to know how to use, it's on the formula sheet in the exams).

[Professor Polonsky]

Heron's formula is one of those 'sure, why not'. It's really not that hard to memorise.

[abcdqdxD]

for the graph y=-[(2)/(5-3x)-1], how has it been dilated?