Encouraging Sign

Today I was working with a student on a problem that started out looking like this:

z=(3+4i)^3

and in the middle it looked something like this:

z=[5(cos53+isin53]^3

and at the end it was nice and tidy, like this:

z= -117+45i 

He finished up the work, and then stared at it and said, "Wow! A few months ago I would never have believed I could look at that and even have an idea what to do with it! Now I can work it and see how it might turn out to be useful in electronics or something."

I smiled and I said, "Never underestimate your capacity to learn."
My student looked at me in amazement and exclaimed, "That's Beautiful! You should write it on the board so everyone can see it. Put it over there on the left so it doesn't get erased!" To humor him, I did.

Then I got thinking, and I decided to make a pretty poster of it for my classroom. So now I have a pretty poster up, and I decided to post it here.