These are a few questions I need help with on a test. I've finished most of the others, but I need help with these please!!
8. The ordered pairs (1, 3), (2, 9), (3, 27), (4, 81), and (5, 243) represent a function. What is a rule that represents this function?
(1 point)
y = x3
y = 3x
y = 3x
y = x + 2
9. The ordered pairs (1, 25), (2, 36), (3, 49), (4, 64), and (5, 81) represent a function. What is a rule that represents this function?
(1 point)
y = (5x)2
y = x + 11
y = x5
y = (x + 4)2
10. Suppose yogurt is on sale for $0.50 a piece and you have a coupon for $0.30 off your total purchase. Write a function rule for the cost of n yogurts. How much would 20 yogurts cost?
(1 point)
C(n) = 0.5n – 0.3; $9.70
C(n) = 0.3n – 0.5; $5.50
C(n) = 0.2n; $4.00
C(n) = 0.5n; $10.00
Tell whether the sequence is arithmetic. If it is, what is the common difference?
14. 2, 7, 13, 20, . . . (1 point)
yes; 5
yes; 6
yes; 2
no
15. 1, 1 1/6, 1 1/3, 1 1/2 (1 point)
yes; –1/6
yes; 1/6
yes; 6
no
8. The ordered pairs (1, 3), (2, 9), (3, 27), (4, 81), and (5, 243) represent a function. What is a rule that represents this function?
(1 point)
y = x3
y = 3x
y = 3x
y = x + 2
9. The ordered pairs (1, 25), (2, 36), (3, 49), (4, 64), and (5, 81) represent a function. What is a rule that represents this function?
(1 point)
y = (5x)2
y = x + 11
y = x5
y = (x + 4)2
10. Suppose yogurt is on sale for $0.50 a piece and you have a coupon for $0.30 off your total purchase. Write a function rule for the cost of n yogurts. How much would 20 yogurts cost?
(1 point)
C(n) = 0.5n – 0.3; $9.70
C(n) = 0.3n – 0.5; $5.50
C(n) = 0.2n; $4.00
C(n) = 0.5n; $10.00
Tell whether the sequence is arithmetic. If it is, what is the common difference?
14. 2, 7, 13, 20, . . . (1 point)
yes; 5
yes; 6
yes; 2
no
15. 1, 1 1/6, 1 1/3, 1 1/2 (1 point)
yes; –1/6
yes; 1/6
yes; 6
no
-
If all else fails, you can try plugging in one or more ordered pairs and see if you get a true statement.
8) You need to recognize the relationship among the y-coordinates. Rewrite them as
(1, 3^1), (2, 3^2), (3,3^3), (4, 3^4), 5, 3^5)
so the rule is y = 3^x. In the future, use "^" to denote a power.
9) Same deal. Recognize a pattern in the y-coordinates. Rewrite them as
(1, 5^2), (2, 6^2), (3, 7^2), (4, 8^2), (5, 9^2)
or even better
(1, (1+4)^2), (2, (2+4)^2), (3, (3+4)^2), (4, (4+4)^2), (5, (5+4)^2)
so the rule is y = (x+4)^2.
10)
C(n) = 0.50n - 0.30
You should confirm that the cost of 20 yogurts is C(20) = $9.70
Your answers for 14 and 15 are correct.
8) You need to recognize the relationship among the y-coordinates. Rewrite them as
(1, 3^1), (2, 3^2), (3,3^3), (4, 3^4), 5, 3^5)
so the rule is y = 3^x. In the future, use "^" to denote a power.
9) Same deal. Recognize a pattern in the y-coordinates. Rewrite them as
(1, 5^2), (2, 6^2), (3, 7^2), (4, 8^2), (5, 9^2)
or even better
(1, (1+4)^2), (2, (2+4)^2), (3, (3+4)^2), (4, (4+4)^2), (5, (5+4)^2)
so the rule is y = (x+4)^2.
10)
C(n) = 0.50n - 0.30
You should confirm that the cost of 20 yogurts is C(20) = $9.70
Your answers for 14 and 15 are correct.