Question

Sendo f(x) - x²-2x+3 obtenha f(-2), f(0), f(1) e f(2+R)

Answer 1

f(x) = - x² - 2x + 3
f(-2) = - (-2)² - 2.(-2) + 3
f(-2) = - 4 + 4 + 3
f(-2) = 3
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f(x) = - x² - 2x + 3
f(0) = - (0)² - 2.0 + 3
f(0) = - 0 - 0 + 3
f(0) =  3
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f(x) = - x² - 2x + 3
f(1) = - (1)² - 2.1 + 3
f(1) = -1 - 2 + 3
f(1) = - 3 + 3 
f(1) = 0
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f(x) = - x² - 2x + 3
f(2 + R) = - (2 + R)² - 2.( 2 + R) + 3
f(2 + R) = - ( 2² + 2.2.R + R²) - 4 - 2R + 3
f(2 + R) = - ( 4 + 4R + R²) - 4 - 2R + 3
f(2 + R) = - 4 - 4R - R² - 4 - 2R + 3
f(2 + R) = - R² - 4R - 2R - 4 - 4 + 3
f(2 + R) = - R² - 6R - 5