Prove that cos 3a = cos (2a+a)cos 3a = 4 cos³a – where from the cos a sin a * cos a give cos a? ? cos 3a = cos (2a +a)cos 2a cos a - sin2a sina(2cos²a-1)cosa-(2sina cos a) sina 2cos³a - cos a - 2 sin²a cos a2 cos³a-cos a - 2(1-cos²a)cos a2 cos³a - cos a - 2cos a + 2 cos³acos3a = 4cos³a-3cos a

Helll ! 1,400 tons of wheat of two different varieties was delivered to the silo. when processing one variety, there was 2% of waste and 3% during the processing of the second variety of wheat. after the processing, the amount of remaining wheat was 1,364 tons. how many tons of each variety of wheat was delivered to the silo?