Sin(A+B)
sinAcosB + cosAsinB
cos(A+B)
cosAcosB - sinAsinB
sin2A
2sinAcosA
cos2A
cos^2 A-sin^2 A
2cos^2 A-1
1-2sin^2 A
arithmetic series : nth term
un = a + (n-1)(d)
geometric series : nth term
un = (a)(r) ^ (n-1)
What are the laws of indices
a^x x a^y = a^x+y
a^x ÷ a^y = a^x-y
(a^x)^y = a^xy
What are log rules
log x + log y =log xy
log x - log y= log x/y
klog x = log (x)^k
What’s the conversion of logs to powers
x = a^n <-> n = loga x
What’s the cosine rule
a^2 = b^2 + c^2 - 2cosA
What’s the area of a triangle
1/2absinC
Sec^2 A =?
1 + tan^2 A
Cosec^2 A =?
1+ cot^2 A
tan2A =?
2tanA / (1 - tan^2 A)