Expand (1 + y) in ascending powers of y as far as the term in y2.

.

1 + 2y + y²

Step-by-step explanation:

Suppose, we want to expand a given binomial of the form;

(1 + y) ⁿ we will have

1 + ny + n (n - 1) y²/2! + n (n - 1) (n - 2) y³/3! + ...

hence:

(1+y) ² = 1 + 2y + 2 (2-1) y²/2!

= 1 + 2y + y²