1. ## Problem to derive

Hello there, I am very sorry if this is the wrong forum, but since I am from sweden our way of naming math courses are very different from the american way. Im reading a course named simply: Math

anyhow my problem is that I have to derive the following

$f(x)=(1+4x)^{1861}(1-7x)^{983}$

if f(0)

Im not sure what to do, do i calculate whats inside the () first or do I derive first? and if i derive first, then how do I do it?

Thanks and sorry once again if this is the wrong forum
Janne the Swede

2. Originally Posted by JannetheSwede
Hello there, I am very sorry if this is the wrong forum, but since I am from sweden our way of naming math courses are very different from the american way. Im reading a course named simply: Math

anyhow my problem is that I have to derive the following

$f(x)=(1+4x)^{1861}(1-7x)^{983}$

if f(0)

Im not sure what to do, do i calculate whats inside the () first or do I derive first? and if i derive first, then how do I do it?

Thanks and sorry once again if this is the wrong forum
Janne the Swede
If you evaluate at x=0 first you just have a number and its derivative is zero as it is no longer a function of x. You differentiate first then substitute x=0.

CB

3. Originally Posted by JannetheSwede
Hello there, I am very sorry if this is the wrong forum, but since I am from sweden our way of naming math courses are very different from the american way. Im reading a course named simply: Math

anyhow my problem is that I have to derive the following

$f(x)=(1+4x)^{1861}(1-7x)^{983}$

if f(0)
"if f(0)" what? Do you mean at x= 0?

Im not sure what to do, do i calculate whats inside the () first or do I derive first? and if i derive first, then how do I do it?
That's a product of two functions so you would use the product rule. And then the chain rule on each factor.

Thanks and sorry once again if this is the wrong forum
Janne the Swede

4. Originally Posted by HallsofIvy
"if f(0)" what? Do you mean at x= 0?

Yea, thats it ^^

Normally at least in our school books they give us the equation

for example f(x)=2x

and then ask us to calculate what the equation is equal to
"if f(2)"
and that is indeed x=2 but explained in a very silly way