Sina - (cosa)(tanb)/cosa + (sina)(tanb)
sina ≡ (tana)(cosa)
(tana)(cosa) - (cosa)(tanb)/cosa + (tana)(cosa)(tanb)
= cosa(tana - tanb)/cosa(1 + tanatanb)
(cosas cancel out)
= (tana - tanb)/(1 + tanatanb) ≡ tan(a-b)
Answer:
We need to find 5 + 10 + 15 + ... + 485 + 490 + 495. There are 99 numbers that are being added. To add this we can do 5 + 495, 10 + 490, 15 + 485 and so on. These pairs have a sum of 500 and since there are 98 / 2 = 49 pairs their sum is 500 * 49 = 24500. Since there is an odd number of numbers that are being added, there is one number that does not belong to a pair. That number is the 50th number in the list which is 50 * 5 = 250. Therefore the answer is 24500 + 250 = 24750.
It’s just 324 x 8 because base x height
2592cm^3
-1x(6x - 8)
= -x(6x - 8)
= -x(6x) - x(-8)
= -6x^2 + 8x
