Evaluate the derivative of the function f(x) = 3/3√x + 3x at the point where x = 8:
a) 47
b) 16
c) 47/16
d) 16/47
2007-04-04 04:57:15 · 4 answers · asked by Laguna B 1 in Science & Mathematics ➔ Mathematics
The function should be written
f(x) = (3/3√x) + 3x at the point where x = 8:
2007-04-04 05:05:37 · update #1
f(x) = 1/sqrt x + 3x = x^(-1/2) + 3x
so:
f' = (-1/2)x^(-3/2) + 3
Now, plug in 8.
f' (8) = 2.9779... approx
2007-04-04 05:01:55 · answer #1 · answered by Mathematica 7 · 0⤊ 0⤋
f(x) = 3/3âx + 3x
is it:
f(x) = 3/(3âx + 3x) ?
or
f(x) = (3/3âx) + 3x ?
2007-04-04 12:00:57 · answer #2 · answered by johnny 2 · 0⤊ 0⤋
Something ain't right. Use parentheses. They are your friend.
2007-04-04 12:02:06 · answer #3 · answered by gebobs 6 · 0⤊ 0⤋
f(x)=3[x^(-1/3)]+3x
f'(x)=3(-1/3)[x^(-4/3)]+3
f'(x)=-1[x^(-4/3)]+3
f'(8)=47/16
2007-04-04 12:05:26 · answer #4 · answered by trojanknight_96 3 · 0⤊ 0⤋