If the product of (x+1)(x**2-2ax+a**2) does not contain x**2, then a=how much.
如果(x+1)(x**2-2ax+a**2)的乘积中不含x**2项，则a=多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>