a) Prove that there exist integers a,b,c not all zero and each of absolute value less than one million, such that
∣a+b2+c3∣<10−11.
b) Let a,b,c be integers, not all zero and each of absolute value less than one million. Prove that
∣a+b2+c3∣>10−21. Putnampigeonhole principlePutnam pigeonhole