A^2 - b^2 = (a - b)( a +b);
<span>cos^4x-sin^4x =( cos^2x + sin^2x )( cos^2x - sin^2x) = 1* cos2x = co2x.</span>
Given an integer, how do u find its opposite....
change the sign
example :
2....its opposite is -2
-3...its opposite is 3
5....its opposite is -5
-4...its opposite is 4
(4a + 6b) x (2a - 2b)
the answer would be 8a2 + 4ab - 12b2
