The Student Room Group
Uni students - Complete our survey >>
Uni students - Complete our survey >>
Uni students - Complete our survey >>

maths question - trial and improvement

iterative.PNG
i got x = 2.8 to 1 d.p is that correct?

Scroll to see replies

Original post by sqrt of 5
iterative.PNG
i got x = 2.8 to 1 d.p is that correct?


No, actual root is 2.8686...
Reply 2
Avatar for sqrt of 5
sqrt of 5
OP
19
Original post by ghostwalker
No, actual root is 2.8686...


????????????? the answer must be to 1 dp
Original post by sqrt of 5
????????????? the answer must be to 1 dp


So, correct to 1 dec.pl. it's 2.9
Reply 4
Avatar for sqrt of 5
sqrt of 5
OP
19
Original post by ghostwalker
So, correct to 1 dec.pl. it's 2.9


it's wrong according to mathswatch
Original post by sqrt of 5
it's wrong according to mathswatch


Which is wrong?
Reply 6
Avatar for sqrt of 5
sqrt of 5
OP
19
I give up i spent a whole evening -.-"
Reply 7
Avatar for sqrt of 5
sqrt of 5
OP
19
Original post by ghostwalker
Which is wrong?


2.9 or the other value you gave to me
Original post by sqrt of 5
2.9 or the other value you gave to me


If you want the root as far as the first decimal place, it's 2.8

If you want it correct to 1 dec.pl. it's 2.9, as that is closer to the actual root than 2.8.

Going to depend on the exact wording of the question.

I'd interpret it as the latter, 2.9
Reply 9
Avatar for sqrt of 5
sqrt of 5
OP
19
Original post by ghostwalker
If you want the root as far as the first decimal place, it's 2.8

If you want it correct to 1 dec.pl. it's 2.9, as that is closer to the actual root than 2.8.

Going to depend on the exact wording of the question.

I'd interpret it as the latter, 2.9


trig 3.PNG
!!
Reply 10
Avatar for Notnek
Notnek
21
Original post by sqrt of 5
trig 3.PNG
!!

You haven't written any working.

Tagging in @Muttley79 who knows more about the bizarre mysteries of MathsWatch so can help if you have further problems :smile:
Reply 11
Avatar for sqrt of 5
sqrt of 5
OP
19
Original post by Notnek
You haven't written any working.

Tagging in @Muttley79 who knows more about the bizarre mysteries of MathsWatch so can help better :smile:


it doesn't matter, it should give a mark for the right answer. Thank you! :smile:
(edited 5 years ago)
Reply 12
Avatar for Notnek
Notnek
21
Original post by sqrt of 5
it doesn't matter, it should give a mark for the right answer

It says "you must show all your working" so I'd try putting in working and see what happens.
Reply 13
Avatar for sqrt of 5
sqrt of 5
OP
19
Original post by ghostwalker
2.9 to 1 decimal place means the root is in the inteval 2.9±0.052.9\pm 0.05, which it is.

Mathswatch is incorrect.


how did you get 2.9 to 1dp? can you show your working out so I can type it into the box?
Original post by sqrt of 5
trig 3.PNG
!!


You need to show working - try x = 2, then x = 3 then 2.5 by substituting in that will tell you whether the root is between 2 and 2.5 or 2.5 and 3. post what you get ...
Reply 15
Avatar for Notnek
Notnek
21
Original post by sqrt of 5
iterative.PNG
i got x = 2.8 to 1 d.p is that correct?

Is this a GCSE question out of interest?
Original post by sqrt of 5
how did you get 2.9 to 1dp? can you show your working out so I can type it into the box?


No, I've no idea what sort of working Mathswatch wants.

If you're not getting 2.9, I suggest posting your working.
Reply 17
Avatar for sqrt of 5
sqrt of 5
OP
19
Original post by Notnek
Is this a GCSE question out of interest?


yep

Original post by ghostwalker
No, I've no idea what sort of working Mathswatch wants.

If you're not getting 2.9, I suggest posting your working.

im trying ill tell you in a bit
Reply 18
Avatar for Notnek
Notnek
21
Original post by sqrt of 5
yep

Trial and improvement isn't part of GCSE maths anymore. Were you set this work? If not then there's probably no point doing it.
Reply 19
Avatar for sqrt of 5
sqrt of 5
OP
19
Original post by Notnek
Trial and improvement isn't part of GCSE maths anymore. Were you set this work? If not then there's probably no point doing it.


:OOOOOOO are you serious? à_à you might be right! the spec only says iterative methods

Original post by ghostwalker
No, I've no idea what sort of working Mathswatch wants.

If you're not getting 2.9, I suggest posting your working.


ok now it does work è_é


@Notnek @ghostwalker @Muttley79 I don't wanna open a new post, can you please give me some hints (not the answer) for this question?

ratio.PNG

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you