Positive and negative
A Benchmark Fraction.If Zero is the description of nothing then it would be a useful reference point as everything else can be clearly defined
The British consult this reference: http://www.ieee.org/portal/cms_docs_iportals/iportals/aboutus/history_center/wesolkowski.pdf Google is a very useful tool when researching.
The human eye, while small, is amazingly complex. An eye diagram is a useful reference for doctors, ophthalmologists, opticians, and the scientifically curious.
If you study trigonometry you learn the definitions of the trigonometric functions by means of the acronym SOH CAH TOA which stands for sine: opposite over hypotenuse; cosine: adjacent over hypotenuse; tangent: opposite over adjacent. This is a very useful acronym.
more useful, the most useful
9 constellations are useful to man, they are useful in showing directions with reference to Pole star.
Directions are used to locate a specific place
Because intermediate directions are more specific
The opposite word for useful is "useless".
The reason why intermediate directions sometimes more useful than cardinal direction is because when you get lost you can use it and find out which way it is.
useless
A very useful thing.
Because u need to know what way is it
The reason why intermediate directions sometimes more useful than cardinal direction is because when you get lost you can use it and find out which way it is.
it is used for reading
Most formulas are copied either down or across, but rarely both directions. If a cell needs to be made permanent in the formula it is usually made absolute, locking both the row and column reference like this: $A$2. However, if a formula is being copied down, then the column reference will not change anyway, so it is not absolutely necessary to lock it, but you would need to lock the row like this A$2. If copying across, then the opposite applies, it is the column reference that needs to be locked, but not the row, like this: $A2. For most formulas it is only necessary to lock one or the other. Depending on the way data is laid out sometimes locking just one element is useful. Like you may have something in a column that needs to multiplied by different fixed values, giving a formula that might be something like this:=$A2*B$2See the related question below for general information about using different reference types.
Yes. Landmarks or skymarks are useful for reference points for locations.