1. Supposedelta> 0.

(a) Prove that there exists a positive integer n such that

0 < 1/((4n+1)pi/2)<delta

and sin ((4n+1)pi/2) = 1

(b) Prove that there exists a positive integer m such that

0 < 1/((4m+3)pi/2)<delta

and sin ((4m+3)pi/2) = -1

see if anyone can do it,