Need derivative help! Anyone?

Question

photon336 · Answer

@Thatonegirl_ what's the question?

thatonegirl_ · Answer

Thank you! 

$$y=\frac{ x^4+6 }{ 3-4x^{-4} }$$

thatonegirl_ · Answer

I already did it, but the answer key is showing a different answer.. So I'm either wrong or it's wrong :S

thatonegirl_ · Answer

And there's one more than is not matching up

satellite73 · Answer

i would get rid of the compound fraction first

thatonegirl_ · Answer

We are learning the difference quotient so i think thats how he wants us to go about this

satellite73 · Answer

not the quotient rule?

thatonegirl_ · Answer

That's what I meant oops

satellite73 · Answer

oh, good, otherwise be almost impossible

thatonegirl_ · Answer

Lol i dont even know what the difference quotient is xD

satellite73 · Answer

$$y=\frac{ x^4+6 }{ 3-4x^{-4} }\
y=\frac{ x^8+6x^4 }{ 3x^4-4 }$$ would be easier

thatonegirl_ · Answer

Oh you just multiplied everything by x^4 to get rid of the negative?

satellite73 · Answer

exactly

thatonegirl_ · Answer

Okay gotcha. 
So then g'(x)=8x^7+24x^3 and h'(x)=12x^3

satellite73 · Answer

yeah

satellite73 · Answer

after that it is a raft of annoying algebra

thatonegirl_ · Answer

$$f'(x)=\frac{ (3x^4-4)(8x^7+24x^3)-(x^8+6x^4)(12x^3) }{ (3x^4-4)^2 }$$

thatonegirl_ · Answer

ahh okay it works out now. Thank you! :)

satellite73 · Answer

yeah good luck with that numerator

satellite73 · Answer

yw

thatonegirl_ · Answer

Lol thx i had like 13 of these to do xD

thatonegirl_ · Answer

So whenever its a - exponent, does it help to just get rid of that first?

thatonegirl_ · Answer

And lets say i have a denominator with a fraction as the exponent.. should i just keep that the same?

satellite73 · Answer

yeah probably

satellite73 · Answer

they are harder to get rid of

thatonegirl_ · Answer

Okay thanks!

satellite73 · Answer

yw