SOLUTION: Hi Can somebody please help me with these, i have attempted them and have answers in mind but unsure? Find df/dx for the following functions i) f(x)= sin(3x-1) I got =

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: Hi Can somebody please help me with these, i have attempted them and have answers in mind but unsure? Find df/dx for the following functions i) f(x)= sin(3x-1) I got =       Log On


   

Question 377688: Hi
Can somebody please help me with these, i have attempted them and have answers in mind but unsure?
Find df/dx for the following functions
i) f(x)= sin(3x-1) I got = cos(3x-1).3
ii) f(x)= sqrt(x^4+1) I got = 1/2(1+x^4)^-1/2.4x^3
iii)f(x)=x/(x+1)^3
Finally
f(x)=tan(x^2+2)
Would appreciate some help on these a great deal
Thanks
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
The first two are correct but could be simplified.
a) df%2Fdx=3%2Acos%283x-1%29
.
.
b) df%2Fdx=%282x%5E3%29%2Fsqrt%28x%5E4%2B1%29
.
.
c) Use the quotient rule,
df%2Fdx=%28%28x%2B1%29%5E3%2A1-%28x%29%283%28x%2B1%29%5E2%29%29%2F%28%28x%2B1%29%5E3%29%5E2
df%2Fdx=%28x%2B1-3x%29%2F%28x%2B1%29%5E4
df%2Fdx=%281-2x%29%2F%281%2Bx%29%5E4
.
.
d)df%2Fdx=%28sec%28x%5E2%2B2%29%29%5E2%2A%282x%29
df%2Fdx=2x%2A%28sec%28x%5E2%2B2%29%29%5E2