3 Sinx - 4Sin³x = 1 - 2Sin²x​

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Aline passes through the point (–7, 5) and has a slope of 1/2 which is another point that the line passes through?

Use mathematical induction to prove the statement is true for all positive integers n, or show why it is false. 1^2 + 4^2 + 7^2 + + (3n - 2)^2 = [n(6n^2-3n-1)/2]