The domain are all valid values for x (the independent variable) that can be used in an equation.
We have to look at any potential values of x which won't work. Easily put: in algebra, just look for values of x which cause either division by zero, or the square root of negative numbers.
A couple of examples:
y=2x+4
You can insert any negative or positive value, or zero, for x and get a valid equation. Therefore the domain is the set of all real numbers. Answers are usually written as:
x: {R}, or simply 'all real numbers'.
what about y=2/(x-1)
In this equation, x appears in the denominator. If x-1=0, then division by zero would occur.
Solve: x-1≠0
x≠1
In set notation:
x: (-∞,1)∪(1,∞)
Parentheses are next to the 1, as the domain comes up to 1, but does not include 1.
Read left to right, the domain is "negative infinity to 1, exclusive, in union with 1 to positive infinity"
4x-7: "seven less than" means you're going to subtract it from the upcoming value, which is "the product of four and a number". "a number" refers to an unknown variable, which I chose to be x. So put it all together and you get 4x-7
6)
34, 43, 52, 61, ...
43-34 = 9; 52-43 = 9; 61-52 = 9
The difference between one term and the next is a constant so it is arithmetic sequence
first term: a = 34
difference: d = 9
so the formula:
7)
10, 6, 2, -2, ...
6-10 = -4; 2-6 = -4; -2-2 = -4
The difference between one term and the next is a constant so it is arithmetic sequence
first term: a = 10
difference: d = -4
so the formula:
8)
-3, -10, -17, -24, ...
-10-(-3) = -7; -17-(-10) = -7; -24-(-17) = -7
The difference between one term and the next is a constant so it is arithmetic sequence
first term: a = -3
difference: d = -7
so the formula:
9)
7, 8.5, 10, 11.5, ...
8.5-7 = 1.5; 10-8.5 = 1.5; 11.5-10 = 1.5
The difference between one term and the next is a constant so it is arithmetic sequence
first term: a = 7
difference: d = 1.5
so the formula:
10)
30, 22¹/₂, 15, 7¹/₂, ...
22¹/₂-30 = -7¹/₂; 15-22¹/₂ = -7¹/₂; 7¹/₂-15 = -7¹/₂
The difference between one term and the next is a constant so it is arithmetic sequence
first term: a = 30
difference: d = -7¹/₂
so the formula:
A dilation is when the figure is enlarged and a reduction is when the figure is reduced, smaller.
The scale factor for dilation is > 1 and reduction >0,<1