1. c, d positive real numbers and c+d=1 prove that (c+1/c)2+(d+1/d)2>=25/2
2. Prove the previous also formulate and prove a generalization for n
3. I first tried to expand but got stuck, I thought of using Binomial but also got stuck. I tried to do (a+b)2 were a=(c+1/c) and b=(d+1/d) but also...