I already solved this but the detailed breakdown helps the general audience. but I am wondering about this now. Why did they say 4,0 is the max. I mean we know quadratic graphs but without doing dy/dx how did they know?y = 1−2x4x = 1−2x4x −2 +2 = 1−2x2(2x−1) +2 = 1−2x2−2(1−2x)= 2⋅ 1−2x1−(1−2x)= (−2)⋅ [1−1−2x1]
Take time to do the algebra "correctly" - without that Calculus will be "far away"!
