Maths Rocks

i have this project and i have to find the rate of entropy generation for a shell and tube heat exchanger....

i need a numerical plus its solution for verification purpose so are there any sites or books from where i can get questions and their solutions?

i wanna know if all lipsticks have lard/pig fat in them and could u plz give a reliable source/website to support ur answer

Are molecular ions only formed by bombardment of electrons.

what are the similarities between radicals and ions.

They seem the same to me

What r the differences between radicals and molecular ions.

plz list as many as u can

One root of the cubic equation z^3 +az +10=0

is 1+2i

i) find 'a' -----a=1

ii) show all the roots on an Argand Diagram

iii) Show that all three roots satisfy the equation

|6z-1| =13 and show the locus rep by this equation

I'm having prob with the (iii) part

abt satisfying and the 6 with the z for the locus

Plz Help!

if we have suppose:

arcsin(sin5pi/3)

would this be equal to 5pi/3

or -pi/3(as told by the calculator)

I think its 5pi/3 because we have a definite value here and bo uncertainities.

if the question says find the principal value of this function

then what would the answer be?

* is there any formula for calculating the no. of triangles that can be formaed in a polygon (eg: octagon :56)

* if we have this equation:

(x-2)^2(x-3)=0

and v have to find the sum of all thr roots then is the sum

2+2+3 OR just 2+3 like do we count 2 as two diff roots or just one root

6,24,60,120,.........

wats the sequence?

How many positive values of x≤2pi make

tan4x=sqrt3?

this does mean that the range for solutions is 0≤x≤2pi?

I get 8 solutions but my teacher says 10.

if u get 10 solutions plz explain how

It has something to do with their graphs but if anyone has an alternate explanation that wud b welcum 2.

Similarly

sin(cos(tan(log(lnx))))=0.017452405.....