onur369's Methods Question Thread :)

[onur369]

Ive got a test on Graphs and Polynomials, no calculator. This is Question 1 of Ch Review of Maths Quest, with a no calc symbol.

[pi]

Binomial theorem would seriously help with this (just a hint)

[onur369]

Still takes a long time, I tend to do full working out.

[brightsky]

If you use the binomial theorem enough, it won't take long, definitely within the time you specified. Also just a tip, make use of Pascal's triangle. It can cut down the time by heaps.

[pi]

If you use the binomial theorem enough, it won't take long, definitely within the time you specified. Also just a tip, make use of Pascal's triangle. It can cut down the time by heaps.

True, just write down Pascal's triangle (shouldn't take more than 30 seconds for up to degree 5)

[m@tty]

No way it would take 30 seconds to write down 15 numbers haha

Always go pascals though it's a lot faster as long as it's less than degree 10 or so..

[onur369]

Hey guys, can you help me with this question. Its attached below.

[pi]

Just did this question (like 1 hour ago)!

By finding the red area, they just mean the two lines on the outside (not the actual area), from memory, y=|3x/2|+6 where x = [-2,2] for the first part. Just 'move this around' for part b.

[onur369]

Thanks bud, +1.

[onur369]

Hey guys I got caught up with another question:

If y=g(x) for x ∈ [-1,3] and y=h(x) for x ∈ [0,4] , then y=g(x) + h(x) is defined for .... ?

[Water]

g(x) + h(x) the domain, would be the intersection of their domains, which should be [0,3]



Ohh, yeah, I forgot to put working out


y= g(x)   Domain = [-1,3]


y= h(x)   Domain = [0,4]


To find the intersection would be quite simple

You look at all the x values that g(x) can have, that is, -1,0,1,2,3

You look at all the x values that h(x) can have, that is, 0,1,2,3,4

Then you do look and match,

We know that g(x) and h(x) have the same domains as 0,1,2,3

Hence we know that the intersection of g(x) and h(x) for it to be defined is 0,1,2,3 = [0,3]

Easier method, is to put the domain on a number line, and see which domains match each other

[Halil]

The intersection of the two domains. Water is right

[pi]

The intersection of the two domains.

A handy trick to know that. Works for sum, difference and product functions.

[onur369]

thanks guys

[Pandabear]

If P(x) = ax^4-x^3+bx^2-x-3, P(2)=-1 and P(-3)=144 then a and b are ??

Could use some help on this one.