Y = sin x + cos x
f´(x)=cos x - sin x
The function is increasing when:
cos x - sin x (is greater than) 0 /: sin x
cot x - 1 (is greater than) 0
cot x (is greater than) 1
Function is strictly increasing for x∈ ( 0, π/4 ) ∪ (π, 5π/4 )
Function is strictly increasing for x ∈ ( π/4, π ) ∪ (5π/4, 2π ).
There were many reasons for this, some because of the respective economies pre-war, some because of where the war was fought, and some because the North won and the South lost.
I believe It’s is false! Hope this helps
The German U-boats blocked British Isle and attacked merchant ships affecting the trading business of US with British, but at some stage the U-boats started to attack ships taking the lives of unarmed passengers, as with the Lusitania ship, which 120 American died. The Germans were asked to stop the attacks but they did not and many US ships sank, shedding off US citizens lives. The submarine warfare enraged the US neutrality which then turned against the German and declared war on March 1 in 1917.
