Posted by kelly on Sunday, June 12, 2011 at 10:13pm.
solve each equation algebraically and check it by substituing into the orignall equation.
Method of your choice by solving.
- pre calculous - Reiny, Sunday, June 12, 2011 at 11:35pm
e^(.035x) = 4
take ln of both sides
ln(e^(.035x)) = ln4
.035x lne = ln4, but lne = 1
x = ln4 / .035 = appr. 39.6
log x^2 = 6
x^2 = 10^6
x = 10^3 = 1000
do logx^4 = 2 the same way
2x-2^-x/2=4 : I have a feeling that is not what you meant, without brackets I cannot tell what the equation is. I think the first term is probably 2^x
Again, I think you meant:
e^x+e^(-x/2) = 4
let e^(-x/2) = y , where y is a positive real number
then e^(x/2) = 1/y
and e^x = 1/y^2
so 1/y2 + y = 4
1 + y^3 = 4y^2
y^3 - 4y^2 + 1 = 0
I used a program to find
y = .54 or y = 3.94 appr. , there is also a negative root which would not be allowed
so e^(-x/2) = .54 or ..... use the other root
-x/2 = ln.54
x = 1.2324 or ......
last question, way too ambiguous without brackets.
Answer this Question
- math - I tried everthing but,I couldnt solve it. Please help me.the answer at ...
- algebra - If LOGx (A)=0.7 and LOGx (B) =0.5 how do I solve LOGx (B/A)
- Math - these are some problems i do not get any help is appreciated. These are ...
- ^Maths^ - If Logx-6 base3=2y and Logx-7 base2=3y, show that x^2-13x+42=72y
- Calculus - Find f'(x) if f(x)= Logx(x^2-5x+6) NOTE: that logx is a sub x
- Pre-Calculus - The Richtr scale was evied y Cahrles F.Richter a American ...
- Calculus - If y=Root of(logx+root of (logx+root of logx.........infinty)...prove...
- maths - helo sir/madam can u help me to solve this problem solve the following ...
- pre algebra - 14 is what percent of 200 100/200 =x/14 read as 100% is to 200 as ...
- mathematics for management - helo sir/madam can u help me to solve this problem ...