The Killer
2012-04-28 07:29:06
ok got a exam monday and cant do a few questions on revision sheet, plz explain how to do them:
1) find X when:
2x√8=2^x
2) evaluate
a) 3^-2
b)27^2/3
16^3/2
masterBB
2012-04-28 07:37:25
3^-2 equals 1 / 3^2
27^2/3 equals 3√(27^2)
16^3/2 equals 2√(27^3)
The Killer
2012-04-28 07:38:53
From: masterBB
3^-2 equals 1 / 3^2
27^2/3 equals 3√(27^2)
16^3/2 equals 2√(27^3)
fancy explaining them? thanks
masterBB
2012-04-28 07:41:51
From: cookies1
fancy explaining them? thanks
x ^ -y is the same as 1 / ( x ^ y)
x ^ z / y is the same
y√(x^z)
The Killer
2012-04-29 13:30:52
anyone know the answer to question one?
Is that as in 2 multiplied by x, multiplied by √8, or 2 multiplied by the xth root of 8?
Cerylin
2012-04-29 13:59:02
If its 2√8= 2^x then you do
Log2√8=xlog2
Log2√8/2=x
x=5/2
If its 2x√8=2^x then i have no idea lol.
Endzior
2012-04-29 14:14:40
If its 2x * √8 = 2 ^ x then you have to know Lambert's W func. Not sure if it's properly written then, because that shit's is REAL business :) Of course you can always try to take those 2 functions on a graph and mark the places where they cross each other :
f(x) = 2 ^ x
g(x) = 4√2 * x
That's the only available solution I guess, judging by your age :) But it's still gonna be hard to get "exact" results. Peace!