Question

Find f.
f'(x) = 20x³ + 1/x, x>0, f(1) = 9
f(x) = ____

Answer 1

Explanation:

f'(x) = 20x³ + 1/x

integrate it, u get

f(x)=5x⁴+ln|x|+c

f(1)==5(1)⁴+ln|1|

=5