Log question (1 Viewer)

[BlueGas]

How do I do this question?

 

[rand_althor]

You have to use the numbers 2 and 5 to get 0.4 and 50.
(Let log(x)=log₇(x))
For (i), log(0.4) = log(2/5) = log(2) - log(5) = 0.36 - 0.83 = -0.47.
For (ii) log(50) = log(25 * 2) = log(5²) + log(2) = 2log(5) + log(2) = 2(0.83) + 0.36 = 2.02.

 

[calamebe]

Just to add something, I wanna say calculating the logarithms on the calculator wont work for instances like ii), where the value is actually 2.01 but the answer will be 2.02 as that is the method the markers want you to use.

 

[psyc1011]

Just to add something, I wanna say calculating the logarithms on the calculator wont work for instances like ii), where the value is actually 2.01 but the answer will be 2.02 as that is the method the markers want you to use.

Reason: givens values of log(2) and log(5) are rounded (both base 7)

 

[BlueGas]

Is there any point to the 0.36 and 0.83 values?

 

[leehuan]

Is there any point to the 0.36 and 0.83 values?

You have to use the numbers 2 and 5 to get 0.4 and 50.
(Let log(x)=log₇(x))
For (i), log(0.4) = log(2/5) = log(2) - log(5) = 0.36 - 0.83 = -0.47.
For (ii) log(50) = log(25 * 2) = log(5²) + log(2) = 2log(5) + log(2) = 2(0.83) + 0.36 = 2.02.

Yeah he substituted them in