Mathematical Vocabulary: Word Domain Translation All the possible inputs or x-values for a function 3 𝑓(𝑥) = 𝑥 Domain (x) Range(y) 2 8 10 1000 -1 -1 Example What are the domains for these functions? 1) √𝑥 − 1 – D: 2) √𝑥 -- D: 3) 𝑥 2 – D: 4) 𝑥 3 – D: Range D: {-1, 2, 10} All the possible outputs or y-values for a function. 𝑓(𝑥) = 𝑥 3 Domain (x) Range(y) 2 8 10 1000 -1 -1 What are the ranges for these functions? 5) √𝑥 − 1 – R: 6) √𝑥 -- R: 7) 𝑥 2 – R: 8) 𝑥 3 – R: < 𝑜𝑟 ≤ This is the symbol that represents “less than (<)” or “less than or equal to (≤).” What are the possible values for the following inequalities? 9) 𝑥 + 1 < 2 The symbol < means that the number you pick has to be strictly less than than the number it is comparing to; for example: 𝑥 < 4 means we can pick numbers from negative infinity to 3.9999999999…. The symbol ≤ means that the number you pick can be less than or equal to the number it is comparing to; for example: 𝑥 ≤ 4 means we can pick numbers from negative infinity to 4. 10) 𝑥 ≤ 20 11) −2 > 𝑥 12) 𝑥 2 + 2𝑥 + 2 ≤ 10 13) √𝑥 < 18 > 𝑜𝑟 ≥ This is the symbol that represents “greater than (>) or “greater than or equal to (≥). " What are the possible values for the following inequalities? 14) 𝑥 + 1 > 2 The symbol > means that the number you pick has to be strictly greater than the number it is comparing to; for example: 𝑥 > 4 means we can pick numbers from 4.0000001 to positive infinity. The symbol ≥ means that the number you pick can be greater than or equal to the number it is comparing to; for example: 𝑥 ≥ 4 means we can pick numbers from 4 to positive infinity. 15) 𝑥 ≥ 20 16) −2 < 𝑥 17) 𝑥 2 + 2𝑥 + 2 ≥ 10 18) √𝑥 > 18 Inverse The inverse means we have to find the operations that “undo” or “reverse” the original function’s operations. The inverse is often denote 𝑓 −1 (𝑥). Write in English and math what the reverse operations are: 19) 𝑓(𝑥) = 𝑥 2 Example: 𝑓(𝑥) = 2𝑥 + 1 20) 𝑓(𝑥) = 2𝑥 2 − 2 The inverse is 𝑓 −1 (𝑥) = 𝑥−1 2 to write this in English: 21) 𝑓(𝑥) = √𝑥 − 1 + 2 we subtract one (the inverse of adding by 1) from both sides and then divide by two (the inverse of multiplying by 2) 22) 𝑓(𝑥) = 2√2𝑥 + 1