Given f(x)= 2x and g(x)= x^2-4, find (f + g)(x) and (f -g)(x).?

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2007-08-29 10:54:19 · 3 answers · asked by blessed 1 in Science & Mathematics ➔ Mathematics

(f + g)(x)= 2x+x^2-4
=x^2+2x-4

(f -g)(x) = 2x-(x^2-4)
= 2x-x^2+4
= -x^2+2x+4

2007-08-29 11:00:01 · answer #1 · answered by cool j 2 · 0⤊ 0⤋

(f +g) (x) = 2x + x^2 - 4
rewrite in decending order of power
x^2 +2x-4
(f -g) (x) = 2x - (x^2 - 4)
change signs
=2x - x^2 + 4
rewrite
= -x^2 +2x+4

2007-08-29 18:00:58 · answer #2 · answered by sugarkins 2 · 0⤊ 0⤋

(f + g)(x) = f(x) + g(x) = x^2 + 2x - 4
(f - g)(x) = f(x) - g(x) = 2x + 4 - x^2

2007-08-29 18:45:37 · answer #3 · answered by Hahaha 7 · 0⤊ 0⤋