Question

Differentiate the function:
f(x)=5tan(x)cos(x)

Answer 1

Tan x = Sin x/Cos x

Answer 2

ok Im not sure what to do next

Answer 3

Im here

Answer 4

5 sinx/cosx-sinx?

Answer 5

U want to diff f(x)=5tan(x)cos(x) and

Tan x = Sin x/Cos x so sub it in, then its simple....

Answer 6

I can't remember what to do afterwords.

Answer 7

Maybe if u think a bit, it will come back to you....

Answer 8

are tan(x) and cos(x) multiplied together in the beginning?

Answer 9

It's your question not mine....

Answer 10

5(1/cos^2)-sin(x)?

Answer 11

Yes, that is simple. Too bad it will not lead to a correct result.

As it is written, with that tangent, there are quite a few holes in the Domain. Everywhere cos(x) = 0, this function does not exist. If we promise to stay away from x = pi/2 + kpi, for k an integer, then we can proceed, but we will not get a derivative for these same values that are NOT in the Domain fo the function.

NOW you can worrk about g(x) = 4*sin(x) which is not quite the same as f(x) = 5*tan(x)*cos(x)

Answer 12

did you see what I wrote is that right?

Answer 13

Not sure what possessed me to write g(x) = 4*sin(x), since obviously it should have been g(x) = 5*sin(x).

I'm not sure what you did, there. Working with g(x) and remembering the Domain, is MUCH simpler.