What is a square root of a number?
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What is a square root of a number?
A square root of a number is a value that, when squared, gives the original number.
E.g. 3 is the square root of 9 because 32 = 3 x 3 = 9.
True or False?
Every positive number has two square roots.
True.
Every positive number has two square roots, one positive and one negative.
E.g. and
True or False?
Cube roots of negative numbers do not exist.
False.
The cube root of a negative number will also be a negative number.
For example, -5 is a cube root of -125.
Define the term reciprocal.
The reciprocal of a number is the number that you multiply it by to get 1.
For example, is the reciprocal of .
How do I estimate a root, e.g. the square root of 27?
You can estimate the root of a number by finding the closest integer roots either side of it.
E.g. To find
and
So is between and
What number do you get when you raise any non-zero number to the power of zero, e.g. 20?
Any non-zero number raised to the power of 0 is equal to 1.
E.g. 20 = 1.
True or False?
If you raise a non-zero number to the power of 1, you get 1.
False.
Any number raised to the power 1 is just itself.
E.g. .
What do you get if you raise a non-zero number to the power of -1,
e.g. 3-1 ?
If you raise a non-zero number to the power of -1 you get the reciprocal of the number.
E.g. .
What do you get if you raise a positive number to the power of ½,
e.g. 51/2 ?
If you raise a non-zero number to the power of ½ you get its positive square root.
E.g. .
What is the index law for ?
If you multiply two powers with the same base number, you add the indices together.
What is the index law for ?
If you divide two powers with the same base number, you subtract one index from the other.
What is the index law for ?
If you raise a power to another power, you multiply the indices.
True or False?
False.
The denominator of an index is the root and the numerator of an index is the power.
What does a number written in standard form look like?
A number in standard form looks like , e.g. .
It is a number between 1 and 10 multiplied by a power of ten.
When a number is written in standard form , which values can be?
For , is at least 1 and less than 10, .
This means there is one non-zero digit before the decimal point.
True or False?
When a number is written in standard form , can be a fraction.
False.
For a number written in standard form, , the value must be an integer.
It can be zero, positive or negative.
When a value between 0 and 1, is written in standard form , what type of number will be?
If a value is between 0 and 1 then when it is written in standard form, will be a negative integer.
E.g. 0.083 would be written as 8.3 x 10-2.
How do you multiply two numbers that are written in standard form and give the answer in standard form using index laws?
E.g.
Multiply together the values of from both numbers and write this in standard form if needed, e.g. .
Use index laws to combine the powers of 10, e.g. .
Multiply the two parts together, e.g. .
Simplify if necessary, using index laws again e.g. .
How do you divide two numbers that are written in standard form and give the answer in standard form using index laws?
E.g.
Divide the values of for both numbers and write this in standard form if needed, e.g.
Combine the powers of 10 using index laws, e.g.
Multiply the two parts together, e.g.
Simplify using index laws again if necessary, e.g.