Hey all,

The selective exam is next week! During this tense but exciting time until the exam, I thought it would be a good idea to have a discussion were we can post formulas from all areas of maths that relate to topics in the sehs exam.I want this to kinda be like the count to 20 mod posts,so we always have different formulas.Would really appreciate this and to start of the discussion here is my formula:

Area of circumference=2πr

    Hi here are the TSA formulas for spheres and cylinders:
    Cylinder 2πr(r + h)
    Sphere 4πr2

    • sui likes this.
    • sui replied to this.

      anisha
      What is tsa?

      oh and formula for area of a triangle=1/2xbxh

          sui ughhh im getting goosebumps as each day passes by

              Honestly I am pretty bad with formulas and actually need to revise a lot of mostly geometric formulas.. 😭 we have a short amt of time, but does anyone have good memory techniques/tips that I can apply to something like formulas?

              • sui replied to this.

                Melona ⭐
                thats why i created this disucssion.memorising techniques would be like writing the formula down and finding questions were u can apply it

                    sui Got it!! Thanks so much for this 🙏

                    Line graph formulas:
                    Distance between 2 points - √((x₂ - x₁)2 + (y₂ - y₁)2)
                    Midpoint of a line - ((x₂ + x₁)/2, (y₂ + y₁)/2)

                      a2 - b2 =(a+b)(a-b)

                      for quadratics
                      x = -b ± √b2 - 4ac / 2a

                      ax2 + bx + c = 0

                      sorry my bad y is equal to the latter formula

                      y=ax2 + bx +c

                      Edit (again) it can be 0 too, can somebody clear this up for me?

                      nah jk jk, point slope formula: y-y1 = x (grad)(x-x1)

                      Simple interest: prt/100
                      And compound interest: P(1 + r/n)nt