solve for x:
ln(x) + x = 4
Can someone please give me an explaination that a high school student may attempt to understand
2006-12-11 15:33:24 · 3 answers · asked by puma 2 in Science & Mathematics ➔ Mathematics
Ok here is the actual question that got in my exam for calculus. The question above is just one of the things i was wondering about while trying to solve this baby:
write y as an explicit funtion of x
xy = e^(x-y) + 4
How in the hell do you do this (no calculators what so ever)
2006-12-11 15:45:29 · update #1
It's impossible to isolate x in that equation using algebraic manipulations. That's because x is both inside and outside the nat. logarithm function; you can't get them into a simple form. You will have to use a root-estimating algorithm like Newton's method, or a graphing calculator, to solve this.
2006-12-11 15:38:08 · answer #1 · answered by jacinablackbox 4 · 0⤊ 0⤋
It's not easy. It is a transcendental equation which means it does not have an algebraic solution. Usually the only way to solve these is by successive approximation or graphically.
2006-12-11 15:38:54 · answer #2 · answered by gp4rts 7 · 0⤊ 0⤋
ln(x) + x = ln(x) + ln e^x = ln(xe^x) = 4,
xe^x = e^4, don't look have a solution to me
2006-12-11 15:49:35 · answer #3 · answered by shamu 2 · 0⤊ 0⤋