Recent content by nicolauslamsiu

Aha, i have missed something. Thanks for ur help@@

Prop: Suppose a and b be vectors in R3. If a·x=b·x for all vector x in R3, then a=b My question if the proposition is always true. And if x is a zero vector, is the proposition still valid?

I've also heard that it is possibly due to the formation of photonic crystals and photonic crystals have band gap which can control the propagation of certain wavelength. I want to know how it can control the wavelength that can propagate through the crystals. Is it something related to bragg's law?

chameleon can change the colour of its skin by changing the structural arrangement of cell layers. I found someone said that the shape of patterns of particles can determine how the light behaves when striking the object. I wonder how it works?

Can a extremely massive star ( eg. thousands solar masses) be formed?

oo) yup... sure... i think i know how to solve now... thanks

Homework Statement Using Fundamental Theorem of Calculus to find the derivative 2. Homework Equations upper limit=x^2, lower limit=4x ∫ { 1 / [1+ (sin t)^2] }dt The Attempt at a Solution two independent variables are involved, how should i find the derivative? [/B]

Apart from the the gravitational pull of the Moon and the Sun on the Earth, does the rotation of moon contribute to the tides?

ok...get it...one more question: the declination and R.A. of a star on a certain day is given. is it possible to find the declination and right ascension of a star some days after?

For stars to be observed in a certain place, the stars must be at a position above the horizon. Yet, how to determine the least value of declination of stars so that stars can be seen?

How to determine the bond angle based on the formula of molecules?

*become greater

Will the value of Q become smaller the K if the concentration is lower?

Co^2+(aq.) + 4cl^-1(aq.) =cocl4^2-(aq.)

I want to ask how will the equilibrium position of the system change if water is added to the system?