Web Analytics

Verified Answer :

Using a graphing tool

Let's graph each of the cases to determine the solution of the problem

case A) \(y=3(2^{x})\)  

see the attached figure N \(1\)

The range is the interval--------> (0,∞)

\(y> 0\)

therefore

the function \(y=3(2^{x})\) is not the solution

case B) \(y=2(3^{x})\)

see the attached figure N \(2\)  

The range is the interval--------> (0,∞)

\(y> 0\)

therefore

the function \(y=2(3^{x})\) is not the solution

case C) \(y=-2^{x}+3\)  

see the attached figure N \(3\)    

The range is the interval--------> (-∞,3)  

\(y< 3\)

therefore

the function   \(y=-2^{x}+3\)    is the solution

case D) \(y=2^{x}-3\)  

see the attached figure N \(4\)  

The range is the interval--------> (-3,∞)  

\(y>-3\)

therefore

the function\(y=2^{x}-3\) is not the solution

the answer is

\(y=-2^{x}+3\)

View image calculista
View image calculista
View image calculista
View image calculista

Answer:

The correct option is C.

Step-by-step explanation:

If a function is defined as

\(f(x)=a^x\)

where, a>0, then the range of the function is greater than 0.

\(a^x>0\)               .... (1)

Option A: Using inequity (1),

\((2)^x>0\)

Multiply both side by 3.

\(3(2)^x>0\)

\(y>0\)

The range of first function is y>0. Therefore option A is incorrect.

Option B: Using inequity (1),

\((3)^x>0\)

Multiply both side by 2.

\(2(3)^x>0\)

\(y>0\)

The range of second function is y>0. Therefore option B is incorrect.

Option C: Using inequity (1),

\((2)^x>0\)

Multiply both side by -1.

\(-(2)^x<0\)                    \((\text{change the sign of inequality})\)

Add 3 on both the sides.

\(-(2)^x+3<3\)

\(y<3\)

The range of first function is y<3. Therefore option C is correct.

Option D: Using inequity (1),

\((2)^x>0\)

Subtract 3 from both the sides.

\(2^x-3>-3\)

\(y>-3\)

The range of second function is y>-3. Therefore option D is incorrect.