tentukan fungsi kuadrat yang memiliki titik puncak (-2,3) dan melalui titik (1,-2)!
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❐ Fungsi Kuadrat
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xp = -b/2a
-2 = -b/2a
4a = b
—
ax² + bx + c = y
a(1)² + b(1) + c = -2
a + b + c = -2
a + 4a + c = -2
5a + c = -2
—
ax² + bx + c = y
a(-2)² + b(-2) + c = 3
4a - 2b + c = 3
4a - 2(4a) + c = 3
4a - 8a + c = 3
-4a + c = 3
—
(-4a + c) - (5a + c) = 3 - (-2)
-9a = 5
a = -5/9
—
b = 4a
b = 4(-5/9)
b = -20/9
—
5a + c = -2
5(-5/9) + c = -2
-25/9 + c = -2
c = 7/9
—
Fungsi kuadratnya,
f(x) = ax² + bx + c
f(x) = -5/9 x² - 20/9 x + 7/9
[answer.2.content]
