Search over 10,000 free study notes

Obviously past papers are key for practice at GCSE. Even old style practice papers are still useful. However it is not enough to just get answers wrong and move on. It is more useful to look up all the vo...

tan^2(x)=1/(cos^2(x))-1 Left hand side of the equation (LHS)=tan^2(x) Use the identity tan(x)=sin(x)/cos(x) and substitute it into the LHS LHS=sin^2(x)/cos^2(x) Use the identity sin^2(x)+cos^2(x)=1 and re...

Group 5 and 6 have a different electronic structure, with group 6 having one extra electron that group 5.

If we look at Hunds rule, which states that electrons must occupy orbitals individually bef...

4x^2 + 8x - 5 = 0 4(x^2 + 2x - (5/4)) = 0 4((x + 1)^2 - 1^2 - (5/4)) = 0 4((x + 1)^2 - (9/4)) = 0 4(x + 1)^2 - 9 = 0 4(x + 1)^2 - 9 = 0 Turning point is at (-1, -9)

Equations: 1). y=x^2+4x-2 2.)y=x+2 x+2=x^2+4x-2 First put equation 1 in equation 2 0=x^2+3x-4 Make one side of the equation equal to 0 0=(x+4)(x-1) Factorise the equations Equations 3).x+4=0 4). x-1=0 One...