Math Help - At what value would the derivative..

1. At what value would the derivative..

1) At what value(s) of x, if any, would the value of the derivative be equal to zero?
A) When x=c and x=e only.
B) When x=b only.
C) When x=a, x=b, x=c, and x=d.
D) When x=a, x=b, and x=d.
Here, I put C.

2) At what value(s) of x would the derivative not exist?
A) When x=c and x=e only.
B) When x=c only.
C) When x=a, x=b, x=d, and x=e only.
D) When x=a, x=b, and x=d only.
Here, I put A.

Am I right on these?

2. Re: At what value would the derivative..

What is the function?

3. Re: At what value would the derivative..

what function? It didnt give a function, just the graph

4. Re: At what value would the derivative..

Hello, salma!

1) At what value(s) of $x$, if any, would the value of the derivative be equal to zero?

A) When $x=C$ and $x=E$ only.
B) When $x=B$ only.
C) When $x=A,\:x=B,\:x=C,\:x=D$
D) When $x=A,\:x=B,\:x=D$
. . Here, I put C. . . . . no

There is a vertical tangent at C.
The derivative is DNE (does not exist).

2) At what value(s) of $x$ would the derivative not exist?

A) When $x=C$ and $x=E$ only.
B) When $x=C$ only.
C) When $x=A,\:x=B,\:x=D,\:x=E$ only.
D) When $x=A,\:x=B,\:x=D$only.
. . Here, I put A. . . . . no

You are half-right.
The derivative is DNE at $x = C.$

But the derivative does exist at $x = E.$

The point itself does not exist.
But you can sketch the tangent line there, can't you?

5. Re: At what value would the derivative..

umm ok I think i got it now, so for the 1st one, would it be D then?
and then the 2nd one would be B