1 Èíòåãðàëû - äèôôåðåíöèàëû

[def]

âîò íàïðèìåð äèàïàçîí õ êîòîðûå ïîäõîäÿò äëÿ íàïðèìåð òàêîãî íåðàâåíñòâà


/x/>2/x-2/

òîëüêî åñëè õ ïðåíàäëåæèò îòðåçêó ÷èñåë (4/3;4)

òîåñòü åñëè ÿ ïîñòàâëþ õ= 2
òî <br>
2> 2*(2-2)
2>0
÷òî âåðíî òàê êàê 2 äåéñòâèòåëüíî áîëüøå ÷åì 0


åñëè ÿ âîçüìó<br>
õ= 1 ( õ < 4/3)òîåñòü íå ïðåíàäëåæàùåå îòðåçêó <br>
òîãäà<br>
1>2(1-2)
1>-2

÷òî íå âåðíî ...



ïîíÿòíî ?

[Vany]

Òû ìåíÿ åùå ñèëüíåå çàïóòàëà=)))

[def]

ïîïðîáóé ðåøèòü òàêîå íåðàâåíñòâî

/x+4/> 5



îòâåòü íà âîïðîñ ïðè êàêèõ õ äàííîå íåðàâåíñòâî âåðíî

[def]

ïðè x íàõîäÿùèìñÿ ìåæäó

-9 è -4

è òàêæå ïðè õ > 1


â ýòîì äèàïîçîíå ïîäõîäèò ëþáîé x


ðèñóåì îñü x òî ÷òî ñ //// îíè ïîæõîäÿò //ïîïðîáóé ïîäñòàâèòü<br>

_________(-9)_/_/__/_/_(-4)____0____(1)_/__/__/_/__/__

[Vany]

ß íåïîíÿë ïî÷åìó -9 è -4

[def]

ðåøàåì ìåäëåííî


;D


/x+4/> 5

õ+4 >= 0
åñëè <br>x >= -4

òîãäà <br>

åñëè x>= -4

òî <br>
x+4> 5

åñëè x< -4

òî <br>
-x-4 > 5

è òîãäà ðåøàåì äëÿ êàæäîãî è ïîëó÷àåì ÷òî <br>

åñëè x>= -4

òî <br>
x+4> 5

x > 5-4

x > 1

ïîëó÷èëè îáëàòü _____(1)_/_/_/_/_/ --- +áåñêîíå÷íîñòü <br>

åñëè x< -4

òî <br>
-x-4 > 5

-x > 9

x < -9

ïîëó÷èëè .... (óïñ ÿ îøèáëàñü íàâåðõó) íî âñå æå

- áåñêîíå÷íîñòü _/_/_/_/_/_(-9)_______

íó êàê ïîíÿòíî <br><br>

[Vany]

à ïîä ñëîâàìè quete ïîìîåìó ÷òî ìû äåëàëè?
À òî÷íåå çà÷åì?

[def]

òàê ïðîñòî îáîçíà÷àþòüñÿ âûäåëåííûå êóñêè ...

à âîîáùåòî ÿ òàì ðåøåíèå ïûòàëàñü äî òåáÿ äîíåñòè ;D

[def]

lim [ (x-1)³ / (2x³ + 3x +1)] =
x-> áåñêîíå÷íîñòè <br>

ðàñêðûâàåì âåðõíèå ñêîáêè.

(x³ - 3x² + 3x -1 ) / (2x³ + 3x +1)

äàëåå ãîâîðèòüñÿ ÷òî ïðè òðåìëåíèè x ê áåñêîíå÷íîñòè x³ ÿâëÿåòüñÿ áåñêîíå÷íî áîëüøîé âåëè÷èíîé áîëüøåãî ïîðÿäêà íåæåëè ñòåïåíè âòîðàÿ è ïåðâàÿ ....

è òîãäà <br>

(x³ - 3x² + 3x -1 ) / (2x³ + 3x +1) = (x³ ) / (2x³ )= 1/2 ïðè x-> áåñêîíå÷íîñòè.


////////////////////////////////////////////////////////

////////////////////////////////////////////////////////


lim [2x/(2x-3)]^3x+1
ðåøàåì

[2x/(2x-3)]^3x+1=

[2x/(2x-3)]^3x * [2x/(2x-3)]¹=

{[2x/(2x-3)]^2/3x }^9/2 * [2x/(2x-3)]¹=

{[2x/(2x-3)]^{2/3x -1} }^9/2 * [2x/(2x-3)]^1+2/9=



{[1/3(2x/(2/3 x-1))]^{2/3x -1} }^9/2 * [2x/(2x-3)]^1+2/9=

{[(2/3 x)/(2/3 x-1)]^{2/3x -1} }^9/2 * [2x/(2x-3)]^1+2/9=


{[(2/3 x +1 - 1)/(2/3 x-1)]^{2/3x -1} }^9/2 * [2x/(2x-3)]^1+2/9=

{[(1 + ( 1/(2/3 x-1) )]^{2/3x -1} }^9/2 * [2x/(2x-3)]^1+2/9=

ïåðâàÿ ñêîáêà ñòðåìèòüñÿ ê e^9/2

âòîðàÿ ê 1


ïîëó÷àåì e^9/2

[Nierva]

Confused...

[moonysshadow]

I don't get it either...

[def]

you must not //it was the help for one of my friend .....
I was need to hepl him with the math .... so it was just the way to help online and fast .

you can get the same help if you need any time //just ask

[Nierva]

Oookay...well, I hope he understands it now.

I'm not doing Maths next year, thank God.