Max and Min Problems help needed (1 Viewer)

[hsc2013]

Hi

Can you guys please help me with these 4 questions from the math in focus tetbook. I spent about an hour doing these questions and my answers were wrong. Can you guys show me the work solutions to these questions as I have an exam tomorrow on geo-calculus?

Thanks

 

[Peeik]

I only had a glance at the second one and my working out for part (a) is shown below. When I get time tonight, i'll do it all.