Question

The cost in dollard, of operating a machine per day is given in the formula C=3t^2 -96t +1024 , where t is the time the machine operates, in hours. What is the minimum cost of running the machine? for how many hours must the machine run to reach the minimum cost?

Answer 1

yes but how do I use it thats what Im confused about

Answer 2

use derivatives to find the turning point of the equation

Answer 3

I need this question for today badly and I cannot figure it out for my life

Answer 4

\(\large C=3t^2−96t+1024\)
\(\large C'=6t−96\)
when C' = 0... its a turning point

\(\large C'=6t−96\)
\(\large 0=6t−96\)
\(\large 96=6t\)
\(\large t=96/6\)

Answer 5

so turning point is at t = 16?

Answer 6

ok thanks but how many hours does it need?

Answer 7

so sub t = 16 back into \(\large C=3t^2 -96 +1024\) to find the minimum cost (at t = 16hrs)

Answer 8

and that would give me the minimum cost?

Answer 9

yep

Answer 10

YOU ARE A GEM

Answer 11

so howd u go?
minimum cost is...?

Answer 12

sec

Answer 13

1696

Answer 14

...?
nuh uh...?

Answer 15

so is that right?

Answer 16

3(16^2)-96 +1024

Answer 17

no, sorry i got a completely different answer, are u sure u did minus not plus for the 2nd term?

Answer 18

3(16^2) - 96(16) + 1024

Answer 19

ohh i forgot the t on 96

Answer 20

256

Answer 21

sweeeet, purfect!

Answer 22

AYYYY

Answer 23

can you help me with another one?

Answer 24

aye, i'll try

Answer 25

A triangle has base 2x+ 1 and height 6x-3. What value of x would give an area of 240m^2?

Answer 26

k, so tell me formula for area of triangle?

Answer 27

A=hbb
2

Answer 28

also, ur triangle look like which pic...?

Answer 29

the thing is its a word question no pics

Answer 30

or there is another question

Answer 31

k, so assume one on left

Answer 32

\(\Large A~ =\frac {~ base~ \times ~height}2\)

Answer 33

can u solve from here...?

Answer 34

(1/2)(2x+1)(6x-3) = 240
multiplying both sides by 2:
(2x+1)(6x-3) = 480
FOIL the left side:
12x^2 - 6x + 6x - 3 = 480
12x^2 - 3 = 480
12x^2 = 483
x^2 = 483/12





x = +/- (6.3443) but for measurements we only have positive

therefore x=6.3443

Answer 35

is this right?

Answer 36

ywah, looks perfect, gimme a sec to check tho

Answer 37

yep perfect, i kept leaving the 1/2 part out, my bad ;)

Answer 38

last one?

Answer 39

please

Answer 40

shoot

Answer 41

the sum of squares of two consecutive integers in 365 . find the value of the intergers.

Answer 42

x^2 + (x+1)^2 = 365... expand out the brackets and solve for x

Answer 43

my teacher teach crap very well. can you show me?

Answer 44

the damm keyboard. * my teacher dosen't tach very well. Could you show me

Answer 45

teach*

Answer 46

x^2 + (x+1)^2 = 365
x^2 + (x+1)(x+1) = 365
x^2 + (x^2+1x+ 1x+1) = 365
x^2 + x^2 + 2x + 1 = 365
2x^2 + 2x + 1 = 365
2x^2 + 2x + 1 - 365 = 0

now use quadratic equation:

Answer 47

so in this case:
a = 2
b = 2
c = -364

Answer 48

so if u plug those values into the quadratic formula, you'll get x = -14
or
x = 13...
so x = 13 sounds much more realistic

so ur 2 consecuative values are x and x+1
so 13 and 14

Answer 49

hold on. Isnt c 1?

Answer 50

nope, 1-365 = -364
you always have to arrange the equation so it = 0, or it doesnt work properly

hey, it's pretty much midnight in oz, catchya and good luck gaz ;)

Answer 51

imma sleep now, sorry

Answer 52

OMG THNX

Answer 53

np, slaters

Answer 54

GIVE YOU A NOBLE PRIZE FOR THAT

Answer 55

lol, blushes ;)
nah, all good hey, good luck with ur study