Question

value of x where the tangent line to the graph of f(x)=-x^2+8x+2 is horizontal.

Answer 1

http://www.enotes.com/homework-help/find-values-x-where-tangent-line-horizontal-graph-304874

Answer 2

i need exp.

Answer 3

Take the derivative and set it to zero.
Use:
\[\frac{d}{dx}x^n = nx^{n-1}\]

Answer 4

2x-8? like that

Answer 5

It would be -2x+8=0

Answer 6

+

Answer 7

then ill divide it?

Answer 8

Yeah, so:
-2x=-8
x=4

Answer 9

oh i get it! ;) thanks soo much.