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Multiple choice 10 points

Multiple choice 10 points-example-1
User JHZ
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1 Answer

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Answer:

f'(x) = 5 x<4

= 2x 4<x<6

= 4 x>6

Domain is all real numbers except 4 and 6

Explanation:

We need to find the derivative of the piecewise function

f'(x) = 5 x<4

= 2x 4≤x≤6

= 4 x>6

Is the function continuous at 4

f(4-) = 5(4) - 6 = 20-6 = 14

f(4+) = 4^2 -2 = 16-2 = 14

this is continuous, so there is no problem with the continuity here

Is the function continuous at

f(6-) = 6^2 -2 = 36-2 = 34

f(6+) = 4(6)+10 = 24+10 = 34

this is continuous, so there is no problem with the continuity here

Now we need to check the derivatives

f'(4-) = 5

f'(4+) = 8

This is not continuous, so we get a piecewise definition for the derivative excluding 4

f'(6-) =12

f'(6+) =4

This is not continuous, so we get a piecewise definition for the derivative excluding 6

User Ecmanaut
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5.7k points