Maths & Physics Help

[astarmathsandphysics]

http://www.corollarytheorems.com/Design/gates.htm
http://www.allaboutcircuits.com/worksheets/trouble_gates.html

[sweetsh]

I would be very delightful if you attach us some notes about MAGNETISM and ELECTIRITY for IGCSE Physics....As we are facing serious problems with them...Beacause of out teacher...

Thank you!!

[astarmathsandphysics]

http://physics.greengates.edu.mx/IGCSE_notes.htm

[geekindahouse]

thank you for all your help:)

[esum0209]

do u have notes on how to do find the formula on linear and quadratic sequence in maths as well?
Thanks for the other notes

[astarmathsandphysics]

Here is an example
3 9 17 27 39 is a quadratic sequence
1st diff 6 8 10 12
2nd diff 2 2 2 2
therefore 2/2=1n^2 sequence
Do an n^2 line 1 4 9 16 25 and take away from original sequence
2 5 8 12 This is a linear sequence with diff 3 therefore it is a 3n sequence. To get the first number in this linear sequence with have to take 1 from this 3 so ans=1n^2+3n-1

4 10 16 22 28 is a linear sequence with 1st diff 6 therefore it is a 6n sequence. take 2 from 6 to get 4 so rule is 6n-4

[sweetsh]

You can solve it by logic

[SGVaibhav]

not that easy to solve by logic

[emi]

in the example above ,, why did u divide by 6 at first and then by 2 at last ?

[astarmathsandphysics]

Divide a 4th differebce line by 4x3x2x1=24

Divide a 3rd difference line by3x2x1=6
divide a 2nd difference line by2x1=2
Divide a 1st difference line by1

[sweetsh]

No I think sequences is an easy thing in Mathematics...

[emi]

an observer at the top of a tower of height 20m sees a man due east if him at an angle of depression of 27 degree . He sees another man due south oh him at an angel of depression of 30 degree. find the distance between the two men on the ground .


this is an Question in the trigonometry can you tell me how to solve it ?? at MS the answer is 52.4 .

thanks

[sweetsh]

Which year is that?

[emi]

i have in our book  at the end of each chapters questions from past papers . they didnt mention any year . so i dont know

[astarmathsandphysics]

an observer at the top of a tower of height 20m sees a man due east if him at an angle of depression of 27 degree . He sees another man due south oh him at an angel of depression of 30 degree. find the distance between the two men on the ground .


this is an Question in the trigonometry can you tell me how to solve it ?? at MS the answer is 52.4 .

thanks

Horizontal distance from tower to 1st man: tan27=o/a=20/a so a=20/tan27=39.25
Horixontal distance from tower to 2nd man=20/tan30=34.64
There is a right angle between these 2 lengths so use Pythagoras theorem
d=sqrt(39.25^2+34.64^2)=52.4m