What is the domain of the function: \(\{(1, 2), (2, 4), (3, 6), (4, 8)\}\)?
A. \(\{1, 2, 3, 4, 6, 8\}\)
B. \(\{1, 2, 3, 4\}\)
C. \(\{6, 8\}\)
D. \(\{2, 4, 6, 8\}\)
---
Which of the following represents a function?
A.
B.
C.
D.
---
What is the range of the function: \(\{(2, 1), (4, 2), (6, 3), (8, 4)\}\)?
A. \(\{1, 2, 3, 4, 6, 8\}\)
B. \(\{1, 2, 3, 4\}\)
C. \(\{6, 8\}\)
D. \(\{2, 4, 6, 8\}\)
---
Suppose \(p\) varies directly with \(d\), and \(p = 3\) when \(d = 5\). What is the value of \(d\) when \(p = 12\)?
A. \(\frac{5}{4}\)
B. \(20\)
C. \(14\)
D. \(\frac{36}{5}\)
---
Given the function \(T(z) = z - 8\), find \(T(-2)\).
A. \(-10\)
B. \(-6\)
C. \(10\)
D. \(6\)
---
The number of calories burned, \(C\), varies directly with the time spent exercising, \(t\). When Dennis walks for 4 hours, he burns 800 calories. Which of the following equations shows this direct linear variation?
A. \(C = t\)
B. \(C = 800t\)
C. \(C = 4t\)
D. \(C = 200t\)
Answer (3)
(1)\\the\ domain:\ \ D=\{1;\ 2;\ 3;\ 4\}\ \ \ \ Ans.\ A.\\\\ (2)\ \ \ ? \ (empty)\\\\(3)\\the\ range:\ \ \ Y=\{{1;\ 2;\ 3;\ 4\}\ \ \ \ Ans.\ B.
( 4 ) d p = co n s t 5 3 = d 12 ⇔ 3 d = 5 ⋅ 12 ⇔ d = 3 5 ⋅ 3 ⋅ 4 = 20 ⇒ A n s . B . ( 5 ) T ( z ) = z − 8 ⇒ T ( − 2 ) = − 2 − 8 = − 10 ⇒ A n s . A . ( 6 ) 800 c a l or i es → 4 h o u rs x → 1 h o u r x = 4 800 c a l or i es ⇒ x = 200 c a l or i es C = 200 ⋅ t ⇒ A n s . C .
Answer:a ;
The domain of the function {(1, 2), (2, 4), (3, 6), (4, 8)} is {1, 2, 3, 4} (Answer B). The range of the function {(2, 1), (4, 2), (6, 3), (8, 4)} is also {1, 2, 3, 4} (Answer B). For the variable relationship, when p = 12 , d = 20 (Answer B).
;
