Help Required!!! (1 Viewer)

[RHINO7]

PLEASE- I can't work out these question-


i) Find the area enclosed by the curve y=square root of (3x-5), the y-axis and the lines y=2 and y=3.


ii)Find the area enclosed between the curve y=1/x^2, the y-axis and the lines y=1 and y=4 in the first quadrant.


iii) Find the area enclosed between the curve y=x^3, the y-axis and the lines y=1 and y=8.

 

[morganforrest]

Someone else may want to correct me if I'm wrong, but this is my understanding of how it's done...

i) This is very similar to a normal integration question. In this instance though, you need to rearrange the equation so that you can integrate with regards to y.
ie...

y^2 = 3x - 5

y^2 + 5 = 3x

1/3.y^2 + 5/3 = x

You would then do this integral...

ie (integral sign from 2 to 3) of 1/3.y^2 + 5/3 = x
(Don't forget to add units on and i would recommend doing a quick sketch of this to make sure you don't miss any areas that may cancel when you do the intergration.)


ii) This is virtually the same as the question above, however you should only include the area of this integral in the first quadrant. Again a diagram will help you picture it, then you need to rearrange and integrate w.r.t y

iii) Again, a similar question...draw a diagram to visualise if you have to...otherwise rearrange and integrate as normal...w.r.t y

Sorry I haven't actually done the integrals, I can't really do them on computer, I find it too slow and tedious. If you're still having troubles, let me know and I'll write out the lines of working.

 

[RHINO7]

I don't want to be rude and appear lazy, but could you please show the working out, it would really help. If you have the time.

 

[m0ofin]

I haven't done these in a long, long while so this could cause me a whole lot of embarrassment. Oh dear.



EDIT: My apologies, the writing is a bit hard to read.

 

[SoulSearcher]

I haven't done these in a long, long while so this could cause me a whole lot of embarrassment. Oh dear.



EDIT: My apologies, the writing is a bit hard to read.

They look alright from here, I have no real issues with it, but then there might be an error T missed, but I doubt that.

 

[m0ofin]

They look alright from here, I have no real issues with it, but then there might be an error T missed, but I doubt that.

Thanks.

What do you mean by "error T"?

 

[watatank]

Thanks.

What do you mean by "error T"?

Transcript error perhaps?

 

[SoulSearcher]

Thanks.

What do you mean by "error T"?

My bad, I meant an error I might have missed. Don't know how the "T" got there.

 

[m0ofin]

I thought you were putting in some 4u jargon, just for kicks.

 

[SoulSearcher]

I don't know any 4 unit jargon

 

[idling fire]

Uhm.. just that last part in (iii)

A= 3/4 * (16-1)
= 11.25

not 12
Apparently there was an "error T" =P

 

[h0nkie]

wow u can teach maths online using text =P ..>< i find it hard to understand

 

[idling fire]

wow u can teach maths online using text =P ..>< i find it hard to understand

True, it is somewhat messy in ASCII.