若二次函数y=3x²-2(mx-1)²的二次项系数与常数项互为相反数,求m的值
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若二次函数y=3x²-2(mx-1)²的二次项系数与常数项互为相反数,求m的值
若二次函数y=3x²-2(mx-1)²的二次项系数与常数项互为相反数,求m的值
若二次函数y=3x²-2(mx-1)²的二次项系数与常数项互为相反数,求m的值
3x²-2(mx-1)²
3x²-2(m²x²-2mx+1)
3x²-2m²x²+4mx-2
(3-2m²)x²+4mx-2
互为相反数的两个数相加等于零
3-2m²-2=0
1-2m²=0
m²=1/2
m=±(√2)/2
3-2m²-2=0 所以m²=1/2
m=正负2分之根号2
y=3x²-2(mx-1)²=(3-2m²)x²+4mx-2
根据题意知3-2m²=2,解出m=正负2分之根号2
y=3x²-2(mx-1)²=(3-2m^2)x^2+4mx-2,由题意
3-2m^2=-(-2)=2,m^2=1/2,
所以m=±√2/2。
y=3x^2-2(mx-1)^2
=(3-2m^2)x^2+4mx-2
所以,3-2m^2=2
解得:m=根号下2
2分之根2