1.设函数y=√x²-5x+4的定义域为().2.设f(x)=3x-5,则f(2x-1)=().3.已知函数f﹙x﹚=x²-1/1+x,则f(1/2﹚=﹙﹚.4.设f﹙x﹚=x²-ax+a,且f﹙2﹚=7,则常数a=﹙﹚.
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![1.设函数y=√x²-5x+4的定义域为().2.设f(x)=3x-5,则f(2x-1)=().3.已知函数f﹙x﹚=x²-1/1+x,则f(1/2﹚=﹙﹚.4.设f﹙x﹚=x²-ax+a,且f﹙2﹚=7,则常数a=﹙﹚.](/uploads/image/z/4944680-8-0.jpg?t=1.%E8%AE%BE%E5%87%BD%E6%95%B0y%3D%E2%88%9Ax%26%23178%3B-5x%2B4%E7%9A%84%E5%AE%9A%E4%B9%89%E5%9F%9F%E4%B8%BA%EF%BC%88%EF%BC%89.2.%E8%AE%BEf%EF%BC%88x%EF%BC%89%3D3x-5%2C%E5%88%99f%EF%BC%882x-1%EF%BC%89%3D%EF%BC%88%EF%BC%89.3.%E5%B7%B2%E7%9F%A5%E5%87%BD%E6%95%B0f%EF%B9%99x%EF%B9%9A%3Dx%26%23178%3B-1%2F1%2Bx%2C%E5%88%99f%EF%BC%881%2F2%EF%B9%9A%3D%EF%B9%99%EF%B9%9A.4.%E8%AE%BEf%EF%B9%99x%EF%B9%9A%3Dx%26%23178%3B-ax%2Ba%2C%E4%B8%94f%EF%B9%992%EF%B9%9A%3D7%2C%E5%88%99%E5%B8%B8%E6%95%B0a%3D%EF%B9%99%EF%B9%9A.)
1.设函数y=√x²-5x+4的定义域为().2.设f(x)=3x-5,则f(2x-1)=().3.已知函数f﹙x﹚=x²-1/1+x,则f(1/2﹚=﹙﹚.4.设f﹙x﹚=x²-ax+a,且f﹙2﹚=7,则常数a=﹙﹚.
1.设函数y=√x²-5x+4的定义域为().2.设f(x)=3x-5,则f(2x-1)=().3.已知函数
f﹙x﹚=x²-1/1+x,则f(1/2﹚=﹙﹚.4.设f﹙x﹚=x²-ax+a,且f﹙2﹚=7,则常数a=﹙﹚.
1.设函数y=√x²-5x+4的定义域为().2.设f(x)=3x-5,则f(2x-1)=().3.已知函数f﹙x﹚=x²-1/1+x,则f(1/2﹚=﹙﹚.4.设f﹙x﹚=x²-ax+a,且f﹙2﹚=7,则常数a=﹙﹚.
1.定义域是x^2-5x+4>=0,(x-1)(x-4)>=0
即有x>=4或x<=1
2.
f(x)=3x-5,f(2x-1)=3(2x-1)-5=6x-8
3.
f(x)=x^2-1/(1+x)
f(1/2)=1/4-1/(1+1/2)=1/4-2/3=3/12-8/12=-5/12
4.
f(2)=4-2a+a=7
a=-3
1.x²-5x+4≥0
(x-4)(x-1)≥0
所以x≥4或x≤1
定义域为(-∞,1],[4,+∞﹚
2.f(2x-1)=3*(2x-1)-5=6x-8
3.f(1/2)=[(1/2)²-1]/(1+1/2)=(-3/4)/(3/2)=-1/2
4.f(2)=2²-2a+a=4-a=7
a=-3
1, x^2-5x+4>=0 x>=4 or x<=1
2,f(2x-1)=3(2x-1)-5=6x-8
3 f(1/2)=(1/4-1)/(1+1/2)=-3/4/(3/2)=-1/2
4f f(2)=4-2a+a=7 a=-3
1.x>=4 or x<=1
2.6x-8
3.-1/4
4.-1/2