f(x) = (sqrt(x))/(x^3+1)
f'(x) = (-2.5x^5/2)+(1/2sqrt(x)) / (x^3+1)^2
f(x) = (cosx/t^3)
f'(x) = (-x^3sinx)-(3x²cosx)/(t^3)²
f(x) = [2-(1/x)]/(x-3)
f'(x) = (-2x²+2x-3)/(x²-3x)²
unsuree if i have done these correctly on my H/W...-thx
And for the second one:
You are forgetting implicit differentiation here. You are differentiating with respect to x, so when you take the derivative of t it will be t' or , but not 1.
You also seem to be changing the t into an x sometimes. Make sure you understand what I did there. If you want me to explain it in more detail, I will.
Hope I helped you