...Hi, I'm working on some problems for reviewing, but I'm not sure if the answers I'm getting are the right one. Please help me check if they're right. If they're not please let me know and I will post my work to see what I have done wrong.

1. Find

ok

2. Find the equation of the line tangent to at

what is "b" ?

3. Find the point P on the graph of closest to the point

so far so good ... and the point is ... ?

4. Calculate the surface area of revolution of about the x-axis over

=

no.