Question

Determine o valor numérico do polinômio P(x)=3x³-5x²+2x-3 para x=-2; x=2; x=1/3 e x=1/2

Answer 1

Resposta:

Explicação passo-a-passo:

p(-2)=

3.(-2)³-5.(-2)²+2(-2)-3=

3.-8-5.4-4-3=

-24-20-4-3=

-44-4-3=

-48-3=

-51

p(2)=

3(2)³-5.(2)²+2.2-3=

3.8-5.4+4-3=

24-20+4-3

4+4-3=

8-3=

5

p(1/3)=

3.(1/3)³-5.(1/3)²+2.1/3-3=

3.1/27 - 5.1/9 +2/3-3=

3/27 -5/9 +2/3 -3=

3/27 - 15/27 + 18/27 - 81/27=

-12/27 +18/27 -81/27=

+6/27-81/27=

-75/27=  (simplifica por 3)

-25/9

p(1/2)=

3.(1/2)³-5.(1/2)²+2.(1/2)-3=

3.1/8 -5 1/4 +2/2-3=

3/8 -5/4 +1 -3 =

3/8 -10/8 +8/8 -24/8 =

-7/8+8/8-24/8=

1/8-24/8=

-23/8