The number of non-negative real roots of $$2^x - x - 1 = 0$$ equals
Solution
$$2^x - x - 1 = 0$$ for this equation only 0 and 1 i.e 2 non-negative solutions are possible. Or we can plot the graph of $$2^x$$ and x+1 and determine the number of points of intersection and hence the solutin.