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dave0616Best ResponseYou've already chosen the best response.1
what is your question?
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
My question is this: USe 5 rectangles to estimate the area under the graph of: f(x) = 2x^3+2x5. from x=2 to x=7
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
And also tell whether your estimate is an over or an upper estimate, explain why?
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
oh you are doing reimann sums? let me do some work, give me a second
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
if you can check with me that I got my 5 rectangles: 35, 93, 193, 92, 128 are they right?
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
hmmmmm im gonna draw up the graph so that we know we have the same thingdw:1366346945142:dw That is the graph that i have, roughly at least, is that the same thing that you are working with?
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
but can you please check my numbers plzz
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
i punched this into my calculator, and the base for each rectangle would be 1, because you are using 5 rectangles, and the difference between 7 and 2 is 5. so you are basicallly looking at the height, but i got 15, 55, 131, 255, and 439. i dont see how you could get any negative because the line is going up
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
yeah i got that too but I m saying that arent we suppose to add up those rectangles?
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
so whats my answer basically?
 one year ago

jojo921Best ResponseYou've already chosen the best response.0
intervals =ba/n (72)/5 =1
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
yea, you just add what you got for the areas, so 15+55+131+255+439=839. and it would be an under estimate because it is a left side reimann sum. meaning that the left corner of the boxes hit the line
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
i thought its over estimate because its increasing
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
dw:1366348904077:dw that isnt to scale, but that is the basic idea of what is going on
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
Use 5 rectangles to esitmate the area under the graph: y=x^310x^2+27x18
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
from 1<equal to x <equalt to 6
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
ok so your graph is going to look like: dw:1366349701319:dw roughly of course.
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
so how am I actually going to solve this
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
are you supposed to use 5 boxes again?
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
yeah its says 5 rectangles
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
does this problem have the same basis as the other problem you posted? meaning you are just looking for rectangles to find the area under the graph? ok, 5 rectangles
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
and it also gives you from where to where
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
which is this dw:1366349945211:dw
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
right, so this again is the same difference as the other problem, (5) so each will have the same base length of 1
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
can we work on this together little bit ?
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
yes of course we can. how would you like to do that? i would like to help you in the best way that suits you
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
can you first show me how to get the value for the 1st rectangle?
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
yes, i personally am using a graphing calculator because i find it is the easiest way to do it. are you using the same, or are you trying to do this by hand?
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
we are not allow to use calculator
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
ok, that is fine, that just means that we are going to have to find the value for y at every point. and our points are going to be 1,2,3,4,5,6. do you think you can solve for y using the equation for these six points? and would you like to solve them on your own, and then post them, and we can compare values?
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
ok so first I m using 1 for my y
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
nope, we are gonna be solving for y, so we are going to plug 1,2,3,4,5 and 6 in for x into the equation
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
so solve for y, using those six values and let me know what you get
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
so let me get their values then I ll tell you
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
ok, and solve for 1,2,3,4,5 that will give us 5 rectangles
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
did you get the values?
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
hmmmm, that first one isnt correct try it again
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
that is correct, now go ahead and fine the y value for 4 and 5
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
did you solve for them? sorry if i am rushing you, i dont mean to be
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
I m sorry my stupid laptop is giving me tough time
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
its all good no worries
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
you need, two more values, but 10 is not correct, you are going to need to solve for 4 and 5. go ahead and do that and let me know what you get
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
that is correct. now we need to find the area of each of those rectangles. and the base of each of those rectangles is 1, so the area of each of those rectangles will be equal to the value, so we have 0,4,0,6,8. so now all we need to do is add those values.
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
so A=0+4+068. what do you get for area?
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
yeah i got that too all of them
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
but then how am i suppose to find an area add them up?
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
and then divide it by some number?
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
we found that the base of each of those rectangles would be 1. and the area of a rectangle is b*h. we found the height by finding the y. so in essence you are multplying each of the values we found (0,4,0,6,8) by one, but they will equal the values themselves. so what wer are actually doing is A=0(1)+4(1)+0(1)6(1)8(1)
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
can you solve for area from that?
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
what do you get for area?
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
thta is right. is that what you were reffering to earlier when you said 10?
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
oh im extremely sorry, i did not realize that is what you were referrring to. i really do feel bad, im sorry. but yes it is 10, and it would still be an under estimate because we used a left corner triangle
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
haha ok. well im glad we went through it still. yes the area under the graph by the estimate of 5 rectangles is 10. do you understand how we came to the answer?
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
yup I completely did thanks a lot:)
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
absolutely no problem!
 one year ago

JaweriaBest ResponseYou've already chosen the best response.0
I should go to sleep now its really late take care bye.
 one year ago

dave0616Best ResponseYou've already chosen the best response.1
i hear ya haha. take care and good luck in your studies
 one year ago
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