The perimeter of an equilateral triangle is 48 inches or less.

Which set describes the domain for w, the width of one side of the triangle?

1. {0 < w ≤ 3}
2. {0 < w ≤ 12}
3. {0 < w ≤ 16}
4. {0 < w ≤ 48}

A
Incorrect. This only indicates the number of sides of the triangle.

B
Incorrect. A triangle has 3 sides. This measure estimates domain for a square.

C
Correct! The greatest value for one side length is 16 units.

D
Incorrect. The sides have to be part of 48.

At 3.6 calories burned per pound of weight each hour, the calories, c, burned in hours, h, by a 125 pound person walking briskly can be modeled by c = 125(3.6) h.

For a walk of up to 5 hours, identify the domain and range.

1. D: { 0, 1, 2, 3} R: { 0,1,2,…1056}
2. D: { 0 ≤ h ≤ 5 } R: { 0 ≤ c ≤ 2250}
3. D: { all real numbers } R: { all real numbers }
4. D: { -5, -4, -3…} R: { 0, 1, 2…2700}

A
Incorrect. The person walks for five hours, not three. Also the time is continuous not discrete.

B
Correct! Domain includes values 0 to 5 and range includes values 0 to 2,250.

C
Incorrect. The domain and range have constraints.

D
Incorrect. Time can't be measured in negative values.

A function is described by the equation f (x) = x² + 5. The replacement set for the domain is {1, 5, 7, 12}. Which of the following is contained in the corresponding set for the range?

A. 0
Incorrect. This quadratic function cannot equal zero.

B. 6
Correct! 6 is in the range set.

C. 7
Incorrect. Make sure you are squaring x, then adding 5.

D. 15
Incorrect. Make sure you are squaring x, then adding 5.