f(x) = -2x^2+5 tentukan A. f (-1) B. Jika f (x)= -45, tentukan nilai x C. Jika f (a)= -3, tentukan a

Materi : Fungsi

f(x) = -2x^2 + 5

f(-1) = -2(-1)^2 + 5
f(-1) = -2(1) + 5
f(-1) = -2 + 5
f(-1) = 3

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f(x) = -2x^2 + 5
-45 = -2x^2 + 5
-45 - 5 = -2x^2
-50 = -2x^2
-50/-2 = x^2
25 = x^2
5 = x

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f(a) = -2a^2 + 5
-3 = -2a^2 + 5
-3 - 5 = -2a^2
-8 = -2a^2
-8/-2 = a^2
4 = a^2
2 = a