Gmat数学题 dataIf b,c,and d are constants and x2 + bx + c = (x + d)2 for all values of x,what is the value of (1) d = 3(2) b = 61我明白怎么出来的,知道b值怎么算出c呢,
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![Gmat数学题 dataIf b,c,and d are constants and x2 + bx + c = (x + d)2 for all values of x,what is the value of (1) d = 3(2) b = 61我明白怎么出来的,知道b值怎么算出c呢,](/uploads/image/z/13331609-17-9.jpg?t=Gmat%E6%95%B0%E5%AD%A6%E9%A2%98+dataIf+b%2Cc%2Cand+d+are+constants+and+x2+%2B+bx+%2B+c+%3D+%28x+%2B+d%292+for+all+values+of+x%2Cwhat+is+the+value+of+%281%29+d+%3D+3%282%29+b+%3D+61%E6%88%91%E6%98%8E%E7%99%BD%E6%80%8E%E4%B9%88%E5%87%BA%E6%9D%A5%E7%9A%84%2C%E7%9F%A5%E9%81%93b%E5%80%BC%E6%80%8E%E4%B9%88%E7%AE%97%E5%87%BAc%E5%91%A2%2C)
Gmat数学题 dataIf b,c,and d are constants and x2 + bx + c = (x + d)2 for all values of x,what is the value of (1) d = 3(2) b = 61我明白怎么出来的,知道b值怎么算出c呢,
Gmat数学题 data
If b,c,and d are constants and x2 + bx + c = (x + d)2 for all values of x,what is the value of
(1) d = 3
(2) b = 6
1我明白怎么出来的,知道b值怎么算出c呢,
Gmat数学题 dataIf b,c,and d are constants and x2 + bx + c = (x + d)2 for all values of x,what is the value of (1) d = 3(2) b = 61我明白怎么出来的,知道b值怎么算出c呢,
yo 少年我来了,
如题,b,c和d都是常数且满足x^2+bx+c=(x+d)^2,此处x可以是任何数,求c值.
其实2次方的表达应该是我这样打哟.
这种题的技巧很简单,这个初中学过的简单的公式你肯定记得,
即(a+b)^2=a^2+2ab+b^2.这题同样适用,右边(x+d)^2=x^2+2xd+d^2=x^2+bx+c,
由此可得,2xd=bx,d^2=c.
由条件1可知,当d=3的时候,(x+d)^2=x^2+6x+9,因此可以得出c来,
接下来看条件2,当b=6的时候,(x+d)^2=x^2+6x+c,注意,这里的6x=2xd的,因此可以得出d=3,这样条件2就和条件1一样了有木有!然后c就算出来了哟.
综上所述,条件1和条件2【单独】都可以得出c值,因此选d.