scientific computing - Solving Exponential equation in MATLAB -

i trying solve exponential equation in matlab part of assignment. easy see equation

exp(-t)+t*exp(-t)-n=0 

would have 2 solutions, 1 greater 0 , 1 smaller.

however, using solve function, matlab returns called lambertw function , can eval() solution below zero, happens not 1 want answer. me here?

thanks in advance answers , comments!

p.s. alternative, thinking using newton-raphson method solve it, wonder how speed comparing solve()?

ziyao wei

lambertw function need. however, multivalued function , has several branches. need choose right branch answer. see my answer another question on how choose different branch solution.