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Mathematics 11 Online
OpenStudy (anonymous):

using five function values estimate

OpenStudy (anonymous):

\[\int\limits_{-3}^{3}\sqrt{9-x ^{2}}\] using: (i)the trapezoidal rule (ii) simpsons rule

OpenStudy (anonymous):

the values are: x -3 -1.5 0 1.5 3 y Sqrt(18) Sqrt(45)/2 3 Sqrt(27)/2 0

OpenStudy (anonymous):

my values maybe wrong so you might have to double check

OpenStudy (angela210793):

Integrations....the thing i hate in most....:S

OpenStudy (anonymous):

my attempt: \[\int\limits_{-3}^{3}\sqrt{9-x ^{2}}\approx \int\limits_{-3}^{-1.5}\sqrt{9-x ^{2}}+\int\limits_{-1.5}^{0}\sqrt{9-x ^{2}}+\int\limits_{0}^{1.5}\sqrt{9-x ^{2}}+\int\limits_{1.5}^{3}\sqrt{9-x ^{2}}\]

OpenStudy (angela210793):

why did u change 3 to -1.5?

OpenStudy (anonymous):

really i think its quite enjoyable :)

OpenStudy (anonymous):

its my attempt using the trapezoidal rule

OpenStudy (angela210793):

it was the lowest grade i had ever taken in math....tht's y i don't like it :S:S...let me try my way plssss

OpenStudy (anonymous):

i have the answer using the easy way now i need to learn this method for an exam lol unfortunantely its not optional

OpenStudy (angela210793):

ok...I have forgotten the formulas anyway...so i can't solve it even though i tried....and i really have never seen this way of solution...maybe u in USA r smarter :P:P

OpenStudy (anonymous):

im not from the US lol

OpenStudy (angela210793):

ok..in that country from wherever u are...u seem to b smarter :P:P

OpenStudy (anonymous):

following from the top i get \[\int\limits_{-3}^{3}\sqrt{9-x ^{2}}\approx 3/4(\sqrt{18}+\sqrt{45}/2)+3/4(3+\sqrt{45}/2)+3/4(3+\sqrt{27}/2)+3/4(\sqrt{27}/2+0)\]

OpenStudy (anonymous):

thats my working for the trapezoidal rule

OpenStudy (dumbcow):

looks good where did the 3/4 come from? shouldnt it be 1/b-a

OpenStudy (anonymous):

the answer in the back: \[\approx12.294\] whilst i get \[\approx16.610\]

OpenStudy (dumbcow):

nevermind

OpenStudy (anonymous):

the rule in my textbook is \[\int\limits_{a}^{b}f(x)dx \approx( (b-a)/2) (f(a)+f(b))\]

OpenStudy (anonymous):

so using this the first part is (-1.5-(-3))/2 =3/4

OpenStudy (dumbcow):

yep thats it

OpenStudy (anonymous):

but my answer is way off im dont know what im doing wrong

OpenStudy (dumbcow):

oh your y values are off x=-3 y=0

OpenStudy (dumbcow):

9-(-3)^2 =9-9

OpenStudy (anonymous):

omg i knew i should have put brackets around them lol

OpenStudy (anonymous):

i will try it again lol

OpenStudy (anonymous):

i have to thankyou again dumbcow you my friend are a genius :)

OpenStudy (angela210793):

O.o I really have never seen this before.....O.o

OpenStudy (anonymous):

well im in australia and we do a wide range of mathematics

OpenStudy (anonymous):

btw the two rules above are just approximations of the integrals theyre always abit off lol

OpenStudy (angela210793):

I HATE integrations..i always will..i hope tht I won't have to solve any of them in math exam :S

OpenStudy (dumbcow):

haha no love for the integrals your welcome and

OpenStudy (anonymous):

lol i actually reckon its a fun part of maths when you get it right. i hate vector geometry

OpenStudy (angela210793):

i hate conical lines as well (is this how u call them?) O.o

OpenStudy (anonymous):

ill assume you mean conics lol

OpenStudy (angela210793):

idk... :$ maybe...let me google a bit plssss

OpenStudy (anonymous):

kk

OpenStudy (angela210793):

hyperbole, ellipse, parabola....these are wht i am talking abt....they r called conics?

OpenStudy (anonymous):

yeah they are theyre not too bad what country are you from

OpenStudy (angela210793):

No they are...too many formulas...then tangents.....i hate them....actually thr's nothing i like in math :P..I'm from Albania/Europe :)

OpenStudy (angela210793):

I learnt another word...thanks :)

OpenStudy (anonymous):

cool it sounds interesting

OpenStudy (angela210793):

:)

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