If C++:

Let 'a' and 'b' be the numbers then

a=a+b

b=a-b

a=a-b .

Which chapter?

Then write cot as  form then as limX->o (sinX)/ X=0 we get the result...here our X=PI/2(1-x) and  happens to be 1-x and x-> 1  .

Got as:4b²cosA- 2(a²-b²)(1+cosA) as from cos A= solve for c;)

When ice ->water heat required and water->ice heat released..

Now energy released:water at 60 to water at 0 : ms(60-0)..similarly calculate for ice also then compare if whichever  energy is in lesser quantity only that much energy is available for the other process since energy released=energy absorbed . 

@shinee:Put x=1 in the expression we have a term 2(1-x) on num so num=0

                                            Simil,         we have sin(1-x)=sinn0=0 on denominator so denominator also equal to zero so overal it it is 0/0 form  .

Not sure of the direct formula but the way to approach it,since the oxidation state on Ni is +2 now CN is a strong ligand which will cause pairing up.

replace x by y and y by x?

a=q/m  (v x B)..B is given.. Let v= v_x i+v_yj+v_zk  with this -3Vx+7Vy=0so put in values and find out so is it -3?

Ya that is the calculated value from STP;)

pl it took seconds to realize they were different questions!..k

S_y=.4m and v_y= 2 so you can find the initial velocity u_y

V_x=u_x..so find the angle both are known  .

you really understood..not bad my explaining capabilities afterall increased!.

Too lazy..hmmmm

Find moles of helium from data given P,V,R,T now this is six times the disintegrated part from thorium,

So find the disintegrated part("a"),Now the left over(undecomposed) number of moles is also given

To find initial: undecomposed number of moles(5*10^-7/232) + a.

Use this in the formula:)

If you still want the entire process tell.

Th-> Pb +6He

given, 8*10^-5ml so find number of moles , this is 6a where a is the disintegration fraction , so amount left is initial-a=5*10^-7/232 grams so find initial moles and half - life is given so use the formula t=2.303/k  log(Ai/Aleft) where k=ln2/T'  T'is the half life  .