Question

f(t)=t-ln(t)
(a) Determine where the function is increasing and decreasing. Remember that ln(t) is only defined for t>0.

(b) Determine where the function is concave up and concave down.

Answer 1

\(f'(t) = 1-\frac{1}{t} \Rightarrow \frac{t-1}{t}\) where t > 0

Answer 2

I need the intervals, not f'. Though I know finding f' is part of it.

Answer 3

I know that increasing is (1, infinity) but I can't figure out decreasing.

Answer 4

all reals except t=0

Answer 5

I don't understand