+37099 Hey Omi67.....when I substitute your answer into the equation I get -2 NOT 2 ......Hmmmmmm
+37099 Hey Omi67.....when I substitute your answer into the equation I get -2 NOT 2 ......Hmmmmmm
I question this step(s)
Substitution 4x = u
u^2 - 2u -1 = 0 u^2 would be 16x^2 NOT 4^(2x) right???
+129839 4x + 4-x = 2
4x + 4-x - 2 = 0
4x + 1/4x - 2 = 0 multiply through by 4x
42x - 2*4x + 1 = 0 let 4x = u
u^2 - 2u + 1 = 0 factor
(u - 1)^2 = 0 take the square root of both sides
u - 1 = 0
u = 1 so
4x = 1 which implies that x = 0
Check.... 40 + 4-0 = 40 + 40 = 1 + 1 = 2
OK......I still disagree with the answers we have so far. I couldn't figure out how to do this MATHEMAICALLY, so I graphed it at Desmos. The only place where the graph = 0 is at + .6358
x= .6358
At x = 0 you would have 4^0 - 1/(4^0) = 1-1 = 0 not = 2
At x = -.6358 you wind up with -2 not 2
Answer x=.6358 (Actually if you use Omi's answer as a POSITIVE .635776652 you will get the right answer)
~ep
