幂函数`````````````````````````
已知幂函数f(x)=x^n 满足3f(2)=f(4),则f(x)的表达式为_________
参考答案:已知幂函数f(x)=x^n 满足3f(2)=f(4),则
3×2^n=4^n,3×2^n=(2^n)^2,(2^n)^2-3×2^n=0
2^n(2^n-3)=0,2^n≠0,∴2^n=3,n=log(2)3
∴f(x)的表达式为f(x)=x^(log(2)3)
已知幂函数f(x)=x^n 满足3f(2)=f(4),则f(x)的表达式为_________
参考答案:已知幂函数f(x)=x^n 满足3f(2)=f(4),则
3×2^n=4^n,3×2^n=(2^n)^2,(2^n)^2-3×2^n=0
2^n(2^n-3)=0,2^n≠0,∴2^n=3,n=log(2)3
∴f(x)的表达式为f(x)=x^(log(2)3)