Algebra Flashcards
What is the equation for profit?
Profit = Revenue – Cost
What is a reciprocal?
a mathematical expression or function so related to another that their product is one; the quantity obtained by dividing the number one by a given quantity.
How does one get a reciprocal?
- To get the reciprocal of a fraction, just turn it upside down.
- In other words swap over the Numerator and Denominator.
√3≈
≈1.7
√2≈
≈1.4
What is an integer?
For GMAT - an integer is simply a non-fraction or a non-decimal.
Four special powers you want to remember:..
1) Anything raised to the power of “1” equals itself.
4231 = 423
2) 1 raised to any power equals 1.
1423 = 1
3) Any number (except zero) raised to the power of zero equals 1.
4230 = 1
4) Zero raised to any power (except zero) equals zero.
0423 = 0
When Dividing powers of the same base
subtract the exponents.
a5 / a3 = a5-3 = a2
When raising a power to another power
multiply the exponents.
For example:
(a2)3 = (a3)2 = a3·2 = a6
A positive exponent
shows that the decimal point is shifted that number of places to the right.
A negative
exponent shows that the decimal point is shifted that number of places to the left.
a^n / a^m =
a^(n-m)
For example, the power 3^(x-2)
could be transformed into the fraction (3^x) /( 3^2)
Average is…
(The sum of terms) / (The Number of Terms)
With direct formulas…
the value of each item in a sequence is defined in terms of its item number in the sequence.
With recursive formulas…
each item of a sequence is defined in terms of the value of PREVIOUS ITEMS in the sequence.
Ex: A(n) = A(n-1) + A
To solve for the values of a recursive sequence…
you need to be given the recursive rule and ALSO the value of one of the items in the sequence.
In a geometric sequence one can find the common ratio by…
dividing a term by the term in front of it.
Prime Numbers: 1 - 29
2 3 5 7 11 13 17 19 23 29
Prime Numbers: 31 - 67
31 37 41 43 47 53 59 61 67
Prime Numbers: 71 - 101
71 73 79 83 89 97 101
What are the three most common binomials on the GRE?
(x-y)(x+y)
(x-y)^2
(x+y)^2
What are the three most common binomial products on the GRE?
(x-y)(x+y) = x^2 + y^2
(x-y)^2 = x^2 - 2xy + y^2
(x+y)^2 = x^2 + 2xy + y^2
Rules for squaring or taking the square root of a fraction that is between 0 and 1.
Squaring a fraction between 0 and 1 makes it smaller, and taking the square root of it makes it larger.
Integer - Perfect Square [to 100]
1 - 1 , 2 - 4 , 3 - 9 , 4 - 16 , 5 - 25 , 6 - 36 , 7 - 49 , 8 - 64
9 - 81 , 10 - 100 , 11 - 121 , 12 - 144 , 13 - 169
