8^1/3 = 2. How?
回答 (14)
✔ 最佳答案
2*2*2=8, that's how
8= 2^3
so, (8)^1/3)=(2^3)^(1/3)
=(2^(3/3))
=2
2³ = 8
2 = 8^(1/3)
OR
Logs are to base 2 in the following :-
If :-
8^(1/3) = 2
(1/3) log 8 = log 2
(1/3) (3) = log 2
1 = 1
8^(1/3) means cubed root of 8
since we want to get rid of this cubed root,we multiply it by 3
i.e
how to factorize 8 such that the power is 3,so as to get rid of the cube ,
since 2*2*2=2^3
{(2^3)^1/3}
both the 3s cancel each other and finally
2!
a^(m/n) = nâa^m
8^(1/3)
= 3â8^1 (3â = extract the cube root)
= 3â8
= 2
Whenever you have and index of a fraction this follows;
x^m/n= nth root of x to the power m
So, in this case;
8 is x,
1 is m
and 3 is n...
Thus: 8^1/3=3rd root of 8 to the power 1
=3rd root of 8
Then; you ask your self; "What number, multiplied by it's self 3 times; is equal to 8."
Answer:2
i.e. 2x2=4
2x2x2=8
8^1/3 means cube root of 8 and thats 2 as 2*2*2=8
8^1/3 is read as cube root of 8...similiarly, 125^1/3 is the cube root of 125 which equals to 5(because cube of 5 is 5 X 5 X 5 = 125)
try not to be confused by this because in the near future u will be doing multiplication of powers XD
1. change 8 to 2^3
2. so, it'll be (2^3)^1/3 = 2
3. then, there's an exponent law that states that (x^y)^z = x^yz *you just multiply the exponent inside the parenthesis and the one outside... that is why, 2^(3/3) = 2
4. 2^1 = 2
5. 2 = 2
收錄日期: 2021-05-01 10:21:09
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