$$\int {{{\log \sqrt x } \over {3x}}} dx$$ is equal to

The equation x³ $$-$$ yx² + x $$-$$ y = 0 represents

The number of points at which the function f(x) = max {a $$-$$ x, a + x, b}, $$-$$ $$\infty $$ < x < $$\infty $$, 0 < a < b cannot be differentiable, is

For non-zero vectors a and b, if | a + b | < | a $$-$$ b |, then a and b are