Sunday

August 31, 2014

August 31, 2014

Posted by **Peter** on Friday, January 20, 2012 at 1:54am.

- Maths -
**Reiny**, Friday, January 20, 2012 at 9:59amtake ln of both sides

ln (3^x) = ln (4^(x-2))

x(ln3) = (x-2)(ln4)

= x(ln4) - 2ln4

xln3 - xln4 = -2ln4

x(ln3 - ln4) = -2ln4

x = -2ln4/(ln3-ln4)

or

x = 2ln4/(ln4 - ln3)

if get appr. 9.638

check:

3^9.638 = appr. 39672.63

4^7.638 = 39676.6

----- close enough using only 3 decimals, if I use my calculator's memory and store the full value of x, my error is 5.9x10^-6

**Related Questions**

Maths - Hey :) I'm sitting my maths non-calculator GCSE tomorrow and am ...

Maths - solve the following pair of simultaneous equation: (x/a)+(y/b)=1 (x/b)+(...

maths - helo sir/madam can u help me to solve this problem solve the following ...

maths - how do i solve this equation? 2/(x+1)=1/(x-1) - (1/(2x-1)) thx Get a ...

maths - solve this equation;5t(6 times 10 neg.3)=(6 times10neg -2) does it look ...

MATHS - Critical help please. Level 3 maths algebraic methods is really hard. Q...

maths - how would i solve the differential equation dx/dt=-kx^2 i.e. solve for x...

maths - Solve the following differential equation: (1 + x)*(dy/dx) = y where y ...

maths - Solve the following differential equation: (1 + x)*(dy/dx) = y where y ...

maths - I don't understand what to do at all, I've several like this if someone ...