Question

已知f(x)=x^4-2x³+3x²-2x+1 计算：f(-1) ,f(1) ,f(-2) ,f(2)

要详细过程，要让7年级学生看懂

Answer 1

解：f(-1)=(-1)^4-2×(-1)³+3×(-1)²-2×(-1)+1
=1-2×(-1)+3×1-2×(-1)+1
=1+2+3+2+1
=9

f(1)=1^4-2×1³+3×1²-2×1+1
=1-2×1+3×1-2×1+1
=1-2+3-2+1
=1

f(-2)=(-2)^4-2×(-2)³+3×(-2)²-2×(-2)+1
=16-2×(-8)+3×4-2×(-2)+1
=16+16+12+4+1
=49

f(2)=2^4-2×2³+3×2²-2×2+1
=16-2×8+3×4-2×2+1
=16-16+12-4+1
=9