Touba M. answered 08/03/21
B.S. in Pure Math with 20+ Years Teaching/Tutoring Experience
Hello,
That's enough you find y' and y"
y = 5x ln(x)
y' = 5 Lnx + 5x* 1/x = 5Lnx +5 = 0 Lnx = -1 x = 1/e by replacing to the function we have
y = 5(1/e ) Ln(1/e) = -5/e so the point is A ( 1/e , -5/e )
y" = (5Lnx +5)' = 5/x by replacing point A y" = 5e >0 so this point A represents to the minimum
I hope it is useful,
Minoo