Question

show that (1+z²)=1+2z+z²
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Answer 1

Answer:

$(1 + {z}^{2} ) \\ = {1}^{2} + 2.1.z + {z}^{2} \\ = 1 + 2z + {z}^{2}$

Answer 2

Answer:

(a + b) 2 = a2 +2ab + b2.

(1 + z) 2 = 1 2 + 2×1× z + z2.

= 1 + 2z +z2.