Never fear, math help is here!

Hello to all the newcomers! I hope you enjoy your stay here. :) I may post a little mathematical exercise once a week for anyone who wants practice (as well as the answer in the comments section), as a way to get people to participate and get the ball rolling.

I've also updated the interests section of the community profile and added a few things. Feel free to leave suggestions!

And now, I leave you with a math joke:

e^x and pi walk into a bar and are surprised to see a differential operator. Suddenly pi exclaims, "We have to leave! I'm only a constant, and if he differentiates me, he's going to cancel me out!"

e^x calmly explains, "Don't worry, let me handle this."

Not intimidated, e^x walks up to the differential operator and tells him, "Hey, you bully! My friend here may be scared of you but I'm not! You can differentiate me all day and I'll still be e to the x!"

The differential operator grins and answers, "Hi, I'm d/dy."

...XD