求助输血120

那琪crystal

120. a=2^4  b=2^a  2^x=a^b 求X   答案有  2^16  2^18 2^32 16^16 ???
思路：
X=4*2^a=2^18

一道很简单的题目，可我怎么就是绕不出来。。。。。

那琪crystal

有人吗有人吗？？？快考了我。。。。。。。。

jganimefan

2^x=a^b

sub in "a" and "b"

given
a = 2^4 then
b = 2^(2^4)= 2^16

therefore
a^b = (2^4)^(2^16)= simplifies to= 2^(2^18)

The question asks given 2^x=a^b what is x, since 2^x=2^(2^18), then x = 2^18

Not sure it this is helpful. I can't type Chinese on this computer. If you don't understand, I can try to use han yu pin yin

sdcar2010

a=2^4  b=2^a  2^x=a^b 求X   答案有  2^16  2^18 2^32 16^16

a = 2^4 = 16

b = 2^a = 2^16

a^b = (2^4) ^(2^16) = 2^(4*2^16) = 2[(2^2)*(2^16)] = 2[2^18] = 2^x

那琪crystal

2^x=a^b

sub in "a" and "b"

given
a = 2^4 then
b = 2^(2^4)= 2^16

therefore
a^b = (2^4)^(2^16)= simplifies to= 2^(2^18)

The question asks given 2^x=a^b what is x, since 2^x=2^(2^18), then x = 2^18

Not sure it this is helpful. I can't type Chinese on this computer. If you don't understand, I can try to use han yu pin yin

-- by 会员 jganimefan (2011/1/7 22:09:31)

我还是不知道a^b = (2^4)^(2^16)= simplifies to= 2^(2^18)这步是怎么简化的？？？谢谢啊，数学知识都忘光了，汗。。。。。