Question

Kerjakan dengan benar pakai cara

Answer 1

Verified answer

Agar fungsi tersebut minimum maka
f'(x) = 0
2nx - 4 = 0
x = 4/2n
x = 2/n

f(x) minimum jika x= 2/n, maka:
n.(2/n)^2 - 4(2/n) +n + 2 = -1
n (4/n^2) - 8/n +n = -3
4/n - 8/n + n = -3 (kali dengan n)
4 - 8 + n^2 = -3n
n^2 +3n -4 = 0
( n+4) (n-1)
n = -4 atau n = 1

syarat f(x) minimum n> 0
maka yg memenuhi n = 1

Answer 2

1. fungsi minimum -1, syarat minimum a>0

F'(x) = 2nx - 4 = 0
x = 2/n

f(x) = nx² - 4x + n + 2
-1 = n(2/n)² - 4(2/n) + n + 2
-1 = 4/n - 8/n + n + 2
-3 = -4/n + n
-3n = -4 + n²
n² + 3n - 4 = 0
(n - 1)(n+4) = 0
n = 1 atau n = -4

syarat minimum: nilai a > 0.

nilai n yg memenuhi:
n = 1