1)Find the absolute extrema of f(x) = sin x - cos x on the interval [ 0,∏ ].
Answer: abs. max at √2 or (sqrt.2) at 3∏/4.
2) State the intervals on which f(x)= cos x - sin x is increasing on the interval [-∏ , ∏], and name all the local extrema.
Could use some advice and help getting started thx.