Maths CORE 3?

Question 1. Log both sides, then find x.

And Question 2 :dontknow:

Reply 2

OP

FinalFlash

Question 1. Log both sides, then find x.

And Question 2 :dontknow:

so ln 3 = ln 7

Reply 3

What exam board are you with?

Reply 4

OP

beatleboar

What exam board are you with?

AQA

Reply 5

student92

so ln 3 = ln 7

3^x=7
Log3^x=Log7
xLog3=Log7
x=Log7/Log3

Are you sure this is a C3 question :confused:

Reply 6

rather game than revise

9

student92

Heya.

1) Solve the equation 3^x = 7, giving your answer to 3 significant figures.

Iterative formulae question:

2) xe^x + x^2 - 1 = 0

Show that x i+1 = 1 / e^xi +xi

is a possible iterative formula for this equation.

Help plzzzz

Thank youuuuuu

For 1)
When you log something raised to a power that power comes down so
a^b=c
b Log a = Log c

Try that for 1.

Reply 7

Pheylan

imaginary numbers in C3 :lolwat:

Reply 8

student92

so ln 3 = ln 7

xln3=ln 7 isn't it ?

Reply 9

FinalFlash

3^x=7
Log3^x=Log7
xLog3=Log7
x=Log7/Log3

Are you sure this is a C3 question :confused:

x=log4
is question 2 actually C3?

Reply 10

OP

FinalFlash

3^x=7
Log3^x=Log7
xLog3=Log7
x=Log7/Log3

Are you sure this is a C3 question :confused:

then would that equal x = ln 4

as its division so you minus the logs?

yeah its core 3.. part of an iterative formula question

Reply 11

Manitude

20

Question 2 requires the use of complex numbers (assuming that for that question i = sqrt-1, not a different constant or variable)

okay, you've already established that.

Consider my post irrelevant then.

Reply 12

OP

beatleboar

x=log4
is question 2 actually C3?

yeah it is.. can't do it :frown:

Reply 13

student92

AQA

Does "i" refer to imaginary numbes? Or just a constant?

Reply 14

student92

then would that equal x = ln 4

as its division so you minus the logs?

yeah its core 3.. part of an iterative formula question

Log7/Log3 =/= Log4 Thats what the calculator says :confused:

ln and log are different btw.

Could you write out the whole question, I'm doing AQA c3 aswell.

Reply 15

student92

then would that equal x = ln 4

as its division so you minus the logs?

yeah its core 3.. part of an iterative formula question

Yes, as if its multpilication you would "add" the logs.
I had a look through my AQA Core 3 Book and there is absolutely no reference to imaginary numbers anywhere.

Reply 16

OP

FinalFlash

Log7/Log3 =/= Log4 Thats what the calculator says :confused:

ln and log are different btw.

Could you write out the whole question, I'm doing AQA c3 aswell.

... trying to scan pic

Reply 17