A student is performing an experiment comparing sound
and light waves. The student gathers the following data
What conclusion does the student most likely make
based on this data?
Medium
Speed of Sound
Temperature
(°C)
0
Ice
Water
Steam
Speed of
Sound (m/s)
3200 m/s
1500 m/s
346 m/s
25
100
Light waves always travel the same speed, however,
the speed of sound is determined by the medium that
it travels through
All sound waves always have the same energy, so
the temperature of the medium does not affect wave
speed
Light needs to vibrate particles, so it travels fastest in
tightly packed solids, while sound does not need a
medium, so it travels fastest in a gas.
Tightly packed particles in solids slow down the light
waves; however, sound waves make particles bounce
into each other, so they travel faster in solids.
Medium
Speed of Light
Index of
Refraction
1.00
1.33
1.57
Air
Water
Glass
Speed of Light
(m/s)
2.99 x 10
2.26 x 10
1.91 x 10
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when functions are first introduced, you will probably have some simplistic "functions" and relations to deal with, usually being just sets of points. these won't be terribly useful or interesting functions and relations, but your text wants you to get the idea of what the domain and range of a function are. small sets of points are generally the simplest sorts of relations, so your book starts with those.

step-by-step explanation:

state the domain and range of the following relation. is the relation a function?

{(2, –3), (4, 6), (3, –1), (6, 6), (2, 3)}

the above list of points, being a relationship between certain x's and certain y's, is a relation. the domain is all the x-values, and the range is all the y-values. to give the domain and the range, i just list the values without duplication:

domain: {2, 3, 4, 6}

range: {–3, –1, 3, 6}

(it is customary to list these values in numerical order, but it is not required. sets are called "unordered lists", so you can list the numbers in any order you feel like. just don't duplicate: technically, repetitions are okay in sets, but most instructors would count off for this.)

while the given set does indeed represent a relation (because x's and y's are being related to each other), the set they gave me contains two points with the same x-value: (2, –3) and (2, 3). since x = 2 gives me two possible destinations (that is, two possible y-values), then this relation is not a function.

note that all i had to do to check whether the relation was a function was to look for duplicate x-values. if you find any duplicate x-values, then the different y-values mean that you do not have a function. remember: for a relation to be a function, each x-value has to go to one, and only one, y-value.

state the domain and range of the following relation. is the relation a function?

{(–3, 5), (–2, 5), (–1, 5), (0, 5), (1, 5), (2, 5)}

i'll just list the x-values for the domain and the y-values for the range: