The Exact Homology Sequence (Exact Sequence of Triples)

Problem: Let X = X_1 / X_2, and A = X_1 / X_2. Using the exact sequence of triples, show that if the inclusion (X_1, A) --> (X, X_2) induces an isomorphism on homology, then the same holds for the inclusion (X_2, A) --> (X, X_1). Notation: X_1 is X subscript 1 / is union / is intersection --> is an inclusion map H_q (X, A) is the quotient module, the qth relative homology module of X mod A Need a step-by-step proof outline.

Vectors in spherical and cylindrical

(a) Given A = a*p_hat + b*psi_hat + c*z_hat (cylindrical unit vectors), where a, b, and c are constants. Is A a constant vector (uniform vector field)? If not, find: the divergence and curl of A (b) If A = a*r_hat + b*theta_hat + c*phi_hat in spherical coordinates, with constant coefficients. Is A a constant vector (uniform vector field)? If not, find: the divergence and the curl of A.

Equivalent paths

(See attached file for full problem description with proper symbols) --- Let be two paths with initial point and terminal point . Prove that iff is equivalent to the constant path at . Note: the path is obtained by traversing the path in the opposite direction. ---

Isomorphism of fundamental groups

(See attached file for full problem description with proper symbols) --- a) Under what conditions will two path classes, and , from to , give rise to the same isomorphism of onto ? b) Let be an arcwise-connected space. Under what conditions is the following true: For any two points , all path classes from to give rise to the same isomorphism of onto ?

Lebesque Number

See attached