(A) 1/2
(B) 3/4
(C) 1
(D) 5/4
(E) 4
1. jika nilai minimum fungsi f(x) = a²cos(x) + a adalah 1/4, maka nilai maksimum f(x) adalah…
Nilai minimum cos(x) =-1
Nilai maksimum cos(x) =1
=a²(-1) + a = 1/4
-a² + a =4
Dilaki 4
=-4a²+4a= 1
=4a²-4a+1=0
= (2a-1)(2a-1) = a = 1/2
Nilai maks.
a² cos(x) + a
(1/2)² ×(1) +1/2
1/4+1/2 = 3/4
Jawaban B = 3/4
Ok?