4 x = 0 . 5 Find out the value of x that satisfies the equation above.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
4^x= 1/2
2*4^x= 1
2*2^(2x) =1
2^(1+2x)= 2^0
So, 1+2x=0 or x=-1/2
Log in to reply
this is an interesting solution though a bit lengthy....
Nice explanation
FYI - To type equations in Latex, you just need to add \ ( \ ) around your math code. In this way, you don't have to use \quad all the time. I've edited your solution so that you can refer to it.
Great work with using Latex :)
nice answer ,dude
nice answer
Simple equation would tell me that if there is a multiple on the left side 4xX=.5 therefore .5 /4 = .125 is the reverse operation.
I got .125 which was rejected as incorrect. Don't. get it and yes 4x.125 = .5 or 1/2
Log in to reply
power of not multiply
It is not 4x = .5 it it 4 to the power of x = .5 4^x=.5 so your logic of dividing is incorrect, if anything you would take the square root of .5 with respect to x or even .5 to the power of 1/x which looks like: .5^(1/x)
smart boy.
THANKsssssssssssssssssss
This one is Really, Really basic logarithms & exponentials, and almost to trivial to bother with!!
i find the contradict solution for this question is to find x value : 4 ^ 1/8 = .5 so x = 1/8 and tat is .125
Formatting failed
4 x = 2 2 x 0 . 5 = 2 1 = 2 − 1 = > 2 x = − 1 = > x = − 2 1 o r 4 x = 0 . 5 = > x lo g 4 = lo g 0 . 5 = > x = lo g 4 lo g 0 . 5 = − 0 . 5
The correct answer but the wrong calculation. Should be log 0.5/log 4.
this is the correct way to solve it thank u
Y o u r a n s w e r h a s b e e n e d i t e d t o t h e c o r r e c t c a l c u l a t i o n
log not required
multiuply both sides by 4
you get
4 x + 1 = = 0 . 5 × 4
so,
4 x + 1 = 2
or,
2 2 x + 2 = 2 1
now, we solve for x
2 x + 2 = 1
2 x = − 1
x = 2 − 1
x = − 0 . 5
"log not required" is a quaint statement because nearly any logarithm problem can be converted into an exponential problem, and vice-versa. That is at the root of the two ideas because exponentials and logarithms are defined to be inverse functions of each other. Hence, a basic thing to do is to find the easiest (or easier) way to solve the problem.
lo g 4 lo g 0 . 5 = − 0 . 5
Finally figured it out using calculator but still struggle to figure out what is really going on.Good answer though Thomas.
4^x =0.5 or 2^2x=1/2 or 2^2x=2^-1 or x=-0.5
but 4^1/2 =root 4 =2
For those saying that calculating log(0.5)/log(4) requires a calculator.
log(0.5)=log(1/2)=log1-log2=-log2
And,
log(4)=log(2^2)=2log2
So,
log(0.5)/log(4)=-log2/(2log2)=-1/2
since 4^(x) = 0.5 2^(2x)=1/2 2^(2x+1)=1 therefore 2x+1=0 2x=-1 x=-0.5
{ 2 }^{ 2x }={ 2 }^{ -1 } =>2x=-1 =>x=-.5
1/sqrt(4) = 0.5, therefore x= -(1/2)
Take log on both side
X log 4= log 0.5;
X=log .5/log 4;
X=-1/2.
But its long version
4^x=0.5we can take both side x so,
4^2x=0.5^x
(2^x) ^2=0.5^x
Now send 2^x to RHS and x will be left over
x=(-2+0.5)^x
x=-0.5
Your solution is not easy to follow. Could you please explain how you got from ( 2 x ) 2 = 0 . 5 x to x = ( − 2 + 0 . 5 ) x ?
0.5=1/2 4^x=0.5 So, first we have to write 4^x in terms of 2 putting x=1/2, we get 2 We have to make it 182, so negative exponent of x gives 0.5 -x=1/2 x=-1/2=-0.5
2(4^x)=2(.5)
2(4^x)=1
first make it 1 then
1 / 2 = .5 and negative since it is an exponent. solve it this way. may be wrong
\sqrt{x}= x^{1/2}
0.5 = 1 / 2
4^{x} = 1/ 4^{-x}
1/2 = 1/4 ^{-1/2}
=> 2^2x = 2 ^ -1 => x=-0.5
4=2^2
so 4x = 2^2x = 0.5
0.5 = 1/2 which is reciprocal of 2 so 2x = -1
x = -0.5
x(log(4)) = log(0.5)
x = log(0.5) / log(4)
x = -0.5
4^x=0.5 4^x=1÷2 2 4^x=1 2 2^2x=2^0 2^(2x+1)=2^0 2x+1=0 X=-0.5
I admit i used the calculator. I was trying without using the calc mas some steps were missing. What can I do from -1 X log4 (2) = x?
Actually u can change d base 4 to 2^2. then take the inverse of this power(in this case 2 to multiply the log. -1x log4 (2) = -1x log2^2 (2) = -1x ½ x log2 (2) = -1 x ½= -½ Remember log2 (2)=1 .tanx
You can use ln to separate x using log rules.
ln4^x = ln0.5
xln4 = ln0.5 (Use log rule that logA^B = BlogA)
x = ln0.5/ln4 (Requires calculator)
x=-0.5
Actually In0.5/In4 can b solved without a calculator using d change of base method. In0.5/In4 = In4 (0.5) = In4 (2^—¹) = -1 x In4 (2) = -1 x In2^2 (2) = -1 x ½ In2 (2) = -1 x ½ = -½
multiply both sides by 4 ,,, so ,,,:-4 /\x+1=2,,, 4/\x+1=4/\1/2,,, x+1=1/2,,, x=-1/2
4^x=0.5,, 2^2x=2^-1,,
2x=-1,, x=-0.5
FIRST METHOD taking LOG in both sides, x log4 = log(1/2) x =log (1/2)/log4 having common base 2, then x =log4(1/2) (here 4 is base). =-1/2 =-0.5 second method is basics of surds.
Note that 0 . 5 = 2 1 = 2 1 1 = 2 − 1 = ( 2 2 ) − 2 1 = 4 − 0 . 5 .
S i n e : 0 . 5 = 4 − 2 1 s o = > 4 x = 4 − 2 1 = > T h e r e f o r e : x = − 2 1 = − 0 . 5 !!!
4^x = 0.5
x = 4 log 1/2
= 2^2 log 2^-1 {sesuai sifat a^m log b^n = m/n(a log b)}
x = -1/2 = - 0.5
We can do this using logarithms too. We know that a ^ x = y implies x = log(y) to the base "a" . Here a=4 and y=0.5=1/2=2^(-1). So x = log(2 ^ ( -1)) to the base log(4). So x = -log(2)/log(4). So x = -log(2) / 2 * log(2) = -1/2 = -0.5
4
x
=
0
.
5
0
.
5
=
1
/
2
=
2
−
1
4
x
=
2
2
x
=> 2x= -1
=> x= -1/2 =
-0.5
take log both side and get ans x log 4=log .5 x=-.5
4^x=1/2, take log to the base 2 on both sides, =>xlog 2^2=log 1 -log 2, 2x log 2= 0 - log2, 2x=-1, x=-0.5, here the base of the log is 2
Taking ln both side of the eqn. ln 4^x=ln(0.5), xln(4)=ln(0.5), x=ln(0.5)/ln(4), x=-0.5
ln4^x=ln(1/2) (Taking log both sides) ln 2^2x = ln 2^-1 2x ln2=-1ln2 now, 2x=-1 x=-1/2=-0.5
4 ^ (- x ) =1 / ( 4 ^ x ) -> 4 ^ 0. 5 = 2 -> 0.5 = 1/ 2 -> 4 ^ (-0.5) = 1 / ( 4 ^ 0.5 ) = 1 / 2 = 0.5
Since it belongs to the category of Logarithms, let's try it using log (whichever base). x*log(4)=log(0.5) x=log(4)/log(0.5) =-0.5
we know that a^b=x then->log x to the base a=b log 0.5 to the base 4=x =>log(1/2)/log 4=x =>(log1-log2)/log 4)=x =>(0-1)/2log2=x (log x^b=blog x) =>-1/2=x
Xlog4=log0.5
x=log0.5/log4
=-0.5
take log on both sides and ul get, x=log(.5)/log(4)
Problem Loading...
Note Loading...
Set Loading...
0.5 can be written as 1/2 and further 1/2 can be written as 2 − 1 .
So 4 x = 2 − 1 2 2 x = 2 − 1 therefore x=-1/2