2022 Paper 1 (13/01/2025) Flashcards
Exact Area of Rhombus using vectors?
Use magnitude of vectors to work out cross sections of the rhombus. Multiplying these by half will produce the height and base of a congruent triangle. Substituting this into the area of a triangle formula and multiplying by 4 will give the area of the rhombus
|f(x)|?
This translation will turn the y-values positive
lim Σ as an integral?
The top and bottom number on the sigma notation become the limits of the integral
Contradiction statement for at least one odd?
Suppose both values are odd
Maximum speed from modelled speed formula?
Differentiate and make the first derivative equal to zero
e^-n x e^n?
1
Arithmetic Series Proof?
Un = a + (n-1)d
Sn1 = (a) + (a+d) + (a+2d) + …. + (a + (n-2)d) + ( a + (n-1)d)
Sn2 = (a+ (n-1)d) + (a + (n-2)d) + …. + (a + 2d) + (a+d) + (a)
2Sn = Sn1 + Sn2
2Sn= (2a + (n-1)d) + (2a + (n-1)d) + (2a + (n-1)d)
2Sn = n(2a + (n-1)d)
Sn = 1/2n (2a + (n-1)d)