Question

Let f(x) = (10 x^2 - 5)/(x^4 + 1).

Then f'(8)=?

Answer 1

f'(x) = [(20x)(x^4+1)-(10x^2-5)(4x^3)] / (x^4+1)^2
Put x = 8 in this equation to get the answer

Answer 2

i got 635/4095= 0.155067155

Answer 3

is that right?

Answer 4

wait that's not right because its says the deriv f'(8)