二次函数y=f(x)的最大值为13
则设f(x)=a(x+b)²+13
f(3)=f(-1)=5
所以f(3)=a(3+b)²+13=5①
f(-1)=a(-1+b)²+13=5
所以a(3+b)²=a(-1+b)²
所以(3+b)²=(-1+b)²
所以9+6b+b²=1-2b+b²
所以8b=-8
b=-1
代入①,解得a=-2
所以f(x)=-2(x-1)²+13
已知二次函数y=f(x)的最大值为13,且f(3)=f(-1)=5,求f(x)的表达式
已知二次函数y=f(x)的最大值为13,且f(3)=f(-1)=5,求f(x)的表达式
数学人气:373 ℃时间:2019-11-18 12:53:31
优质解答
我来回答
类似推荐
猜你喜欢
- 1北师大版九年级数学下册习题1.
- 2Life is like a train.It will always goes around even there is someone left behind
- 3()除以12等于4分之3等于36分之27等于48分之36
- 4小刚.小明和小红共有50元.小刚线拿出小明相等的钱给小明,小明再拿出小红相等的钱给小红,小红最后拿出于小刚相等的钱给小刚,之后他们的钱数相等,求他们原来有多少钱?
- 5So she can help our teachers a l____.
- 6a rainbow is not a thing which we can feel with our hands as we can feel a flower 的中文意思
- 7用加减消元法(1)2x-y=8 2x+5y=-4 (2)2x+5y=17 2x-3y=1 (3)x-y=5 2x+3y-15=0
- 8It is a regret that we haven't received . It is regret that I haven't receive 大家看看这两句话
- 9已知绝对值x-4+绝对值Y+1=0求X的3次方Y的2001次方
- 10小学修改病句练习题