It is theoretically possible for a substance to have a negative value of cubical expansivity, which means that the substance would contract rather than expand when the temperature increases. However, it is very rare for a substance to have a negative value of cubical expansivity over a significant range of temperatures.

One example of a substance that has a negative value of cubical expansivity over a limited range of temperatures is water. Water has a positive value of cubical expansivity at...

Sigma bond is stronger than Pi bond because of the following reasons:

1. The extent of overlapping in Sigma bond is greater than in Pi bond.
2. The electron density in intermolecular axis is more in Sigma bond than in Pi bond.
3. There is free rotation of atom about Sigma bond but not about Pi bond.

Here, the given equation of parabola is y²= 8x.

The equation of tangent to the parabola y²=8x is,

y= mx + 2/m

This tangent passes through the point (-2, 3)

So, 3 = -2m + 2/m

or, 3m + 2m² = 2

or, 2m²+3m - 2= 0

or, 2m² + (4 - 1)m -2 = 0

or, 2m² + 4m - m - 2 = 0

or, 2m(m + 2) - 1(m+2) = 0

or, (m + 2) (2m - 1) = 0

Either, Or,

m = -2 m = 1/2

Required angle is,

Pteridophytes

सेवाहरूमा नैतिकता, मनोविजञान, फिजियोलोजी, मानवविजञान अनतरगत सामाजिक अधययनको पराथमिक उददेशय युवाहरूलाई जानकारी र कारण पुरयाउन मददत गरनु हो I सामाजिक अधययन विजञानको शाखा हो जुन समाज र वयकतिहरू बीचको समबनधको अधययनमा समरपित छ I सामाजिक अधययन पहिले समाजको मौलिक विजञान र समाजशासतरको कषेतरलाई सनदरभ गरन परयोग गरिएको थियो I समाजशासतर बाहेक अब सामाजिक अधययनले 

 समेटने विषयहरुको एक विसतृत शृंखला देखन पाइनछ I ती मधये केही अरथशासतर वयवसथापन चिनह, मानव भूगोल,मिडिया अधययन, राजनीतिक विजञान, मनोविज...