IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => IGCSE/ GCSE => Math => Topic started by: fahadali on May 17, 2009, 04:48:29 pm

Title: maths paper 4 help
Post by: fahadali on May 17, 2009, 04:48:29 pm

Hi

I was wonder when solving the question paper to what correct decimal point should i answer the question ?

e.g: 24.5059595958

p.s: I'm talking about the questions where they don't tell me to what decimal point should i write, which is in most questions XD


the second thing is in trigonometry:

I'm not sure when I can use Sin, Cos, Tan ?

should it be a right angle triangle ?

and the last thing what's the formula for compound interest ?

Title: Re: maths paper 4 help
Post by: vids on May 17, 2009, 04:50:13 pm

Quote from: fahadali on May 17, 2009, 04:48:29 pm

Hi

I was wonder when solving the question paper to what correct decimal point should i answer the question ?

e.g: 24.5059595958

p.s: I'm talking about the questions where they don't tell me to what decimal point should i write, which is in most questions XD


the second thing is in trigonometry:

I'm not sure when I can use Sin, Cos, Tan ?

should it be a right angle triangle ?

and the last thing what's the formula for compound interest ?

soh cah toa
o=opp
a=adj
h=hyp

24.5

Title: Re: maths paper 4 help
Post by: fahadali on May 17, 2009, 04:51:48 pm

what about compound interest ?

Title: Re: maths paper 4 help
Post by: vids on May 17, 2009, 04:51:55 pm

P(1+{r/100})^n
p=principle
r=rate of interest
n=no. of years

hope this helps

Title: Re: maths paper 4 help
Post by: vids on May 17, 2009, 04:52:58 pm

gotta go

Title: Re: maths paper 4 help
Post by: Q80BOY on May 17, 2009, 04:56:34 pm

Quote from: fahadali on May 17, 2009, 04:48:29 pm

Hi

I was wonder when solving the question paper to what correct decimal point should i answer the question ?

e.g: 24.5059595958

p.s: I'm talking about the questions where they don't tell me to what decimal point should i write, which is in most questions XD


the second thing is in trigonometry:

I'm not sure when I can use Sin, Cos, Tan ?

should it be a right angle triangle ?

and the last thing what's the formula for compound interest ?

1. round it to 1 or 2 decimal points

2. see the attched image, sin = opp / hyp
                                   cos = adj / hyp
                                   tan = opp / adj

Title: Re: maths paper 4 help
Post by: sweetsh on May 17, 2009, 04:57:57 pm

Some old horses can always hear their owners' arriving.

Title: Re: maths paper 4 help
Post by: Q80BOY on May 17, 2009, 05:01:51 pm

Quote from: sweetsh on May 17, 2009, 04:57:57 pm

Some old horses can always hear their owners' arriving.

waa  ???

Title: Re: maths paper 4 help
Post by: fahadali on May 17, 2009, 05:03:30 pm

Quote from: Q80BOY on May 17, 2009, 04:56:34 pm

Quote from: fahadali on May 17, 2009, 04:48:29 pm

Hi

I was wonder when solving the question paper to what correct decimal point should i answer the question ?

e.g: 24.5059595958

p.s: I'm talking about the questions where they don't tell me to what decimal point should i write, which is in most questions XD


the second thing is in trigonometry:

I'm not sure when I can use Sin, Cos, Tan ?

should it be a right angle triangle ?

and the last thing what's the formula for compound interest ?

1. round it to 1 or 2 decimal points

2. see the attched image, sin = opp / hyp
                                   cos = adj / hyp
                                   tan = opp / adj

thanks for the help but what i mean in the tan, does the triangle have to be right angle triangle ?

thank you :)

Title: Re: maths paper 4 help
Post by: Q80BOY on May 17, 2009, 05:07:22 pm

no, to use the tan, u need to have values for the opposite and the adjacent

get it?

Title: Re: maths paper 4 help
Post by: angell on May 17, 2009, 05:10:38 pm

june 2000 q.3 d)iii PLEASE

Title: Re: maths paper 4 help
Post by: fahadali on May 17, 2009, 05:19:09 pm

Quote from: Q80BOY on May 17, 2009, 05:07:22 pm

no, to use the tan, u need to have values for the opposite and the adjacent

get it?

ya thanks for the help :D

Title: Re: maths paper 4 help
Post by: care on May 17, 2009, 05:33:42 pm

In order to use sine, cosine and tangent, you have to have a right-angle triangle.

However, the sine and the cosine rules are applied on non-right-angle triangles.