Jazmine G.

asked • 12/20/16

which of the following equations represents a graph that decreases most rapidly?

A. y=-2*2^x-24 B. y=-3*2^x+16 C. y=-1/2*2^x-4 D. y=-1*2^x+12

Philip P.

tutor
Is there an x somewhere in those equations, such as y = 2x2-24?  As written, each y has only a single value and is neither increasing nor decreasing.
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12/20/16

Jazmine G.

yes I messed up on the equations 
 
A. y=-2*2x-24 
B. y=-3*2x+16 
C. y=-1/2*2x-4 
D. y=-1*2x+12
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12/20/16

2 Answers By Expert Tutors

By:

Kenneth S.

I think gregg's answer is untrue.
consider this table, which shows y values for each function, when x=0 & when x=1
 
function:    A    B    C     D
when x=0 -26  13  -4.5  11
when x=1 -28  10   -5    10
 
Here are the decreases for A, B, C, D as x goes from 0 to 1:
                2     3     ½    1
 
Does this convince you that "B" decreases the most?
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12/21/16

Gregg K.

tutor
Let's look at the ratio of function values rather than the difference of function values to determine the answer. As X gets large the ratio of function values is the same for all functions for consecutive integers
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12/21/16

Gregg K.

tutor
For small values of x Let's ignore the constants on the end as stated above and the ratio of function values is the same for all functions we do not have to ignore this constant as X gets large because as X gets large this constant becomes negligible
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12/21/16

Kenneth S. answered • 12/20/16

Tutor
4.8 (62)

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