Question

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

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Answer 1

1 + 2y + y²

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