Question

Tolong dibantu no 4 dan 5 dengan jawaban yg benar dan lengkap soalnya belum terlalu ngerti

Answer 1

No. 4
misal  kurva y = ax² + bx + c

pers sumbu simetri x = - 6 --> x = -b/2a --> -6 = -b/2a
-b = -12 a
b = 12 a

(-8, 5)--> 64a - 8b + c = 5
(-2, 11) --> 4a - 2b +c = 11
............................(-)
60 a - 6b = - 6  dan b = 12 a
60a - 6(12a) = - 6
-12a = -6
a = 1/2
b = 12 a = 6

4a  -2b +c = 11
4(1/2) - 2(6) + c = 11
2 - 12 + c = 11
-10 + c = 11
c = 11 + 10
c = 21

pers kurva y = 1/2 x²  +6x + 21