There is, for sure, effect of gravity on fire. We know for a fact that fires on Earth are "pointy" while those in zero-gravity are "round". This is because fire is simply glowing gas. Gas is matter and matter has weight. For a body to have weight, gravity must influence it in some way. 

Here, f(x)=x² -6 logx-3=0

f(2)=4-6 log2-3=-0.806

f(3)=9-6 log3-3=3.1373

f(2).f(3)=-0.806*3.1373=-2.529422 which is negative.

Hence, the root lies between 2 and 3

c₀ =(2+3)/2=2.5

f(2.5)=6.25-6 log 2.5-3=0.8623

Now

n	a(-ve)	b(+ve)	cn	f(cn)
0	2	3	2.5	0.8623
1	2	2.5	2.25	-0.050595
2	2.25	2.5	2.375	0.38664
3	2.25	2.375	2.3125	0.1631658
4	2.25	2.3125	2.28125	0.05506
5	2.25	2.28125	2.265625	0.001925

From the table,

f(2.265625)=0.001928<10^-2

Therefore, the...

Well, the propagation of light is fundamentally due to oscillation of electric field and magnetic field perpendicularly, which allows the light waves to propagate in the direction perpendicular to both the existing fields, i.e. light waves propagation solely depends on these fields.

But, sound waves are non other than the transference of energy due to disturbance, as well the propagation of sound wave has already been found to be adiabatic in nature, and through the adiabatic equation,...

Yes, if the angle between the two vectors is more than 90^o but less than 270⁰. (cosΘ is negative)