Question

if the straight line parallell x axis and its derivative 0 why?
if the straight line parallell y axis its derivative infinity why?

Answer 1

derivative is a formula for the slope
if the function is a line, the slope is a constant
if the line is parallel to the x axis, the slope is 0

Answer 2

i should day "derivative is a formula for the slope of the line tangent to the graph at a point"

Answer 3

Perhaps if you just think of it as "tan".....

Answer 4

i got a tan
like jackie chan

Answer 5

:-)

Answer 6

What does op think?

Answer 7

I'm not really sure whay you mean by "derivative" here.
In simple way, slope is rise/run so you could say then that for a vertical line (tan 90) it is undefined.

Answer 8

Derivative is the gradient. Therefore Change in y/Change in x.
For a line going straight up.
Change in y is Infinity for every (virtual 1 or even 0 x) you go up.

So infinity/(0 or 1)=infinity