- #1

unf0r5ak3n

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## Homework Statement

a) Write down the definition of "critical point." Find all critical points of ƒ(x).

b) Use the first derivative test to find the x-vale of which ƒ(x) has a minimum.

c) Is ƒ(x) differentiable at x = 7? Justify your answer.

## Homework Equations

ƒ(x)={(0.3125(x-5)^2 + 1.3, x<7)

and (1.25x -6.25, x (> or equal to) 7)}

## The Attempt at a Solution

Not sure how to do this, all I know is the definition of a critical point: points of a function where the function if not differentiable or its derivative is zero.