Formula To Memorise Flashcards
Length equation
root[(x2-x1)^2+ (y2-y1)^2]
midpoint equation
[(x1+x2)/2 , (y1+y2)/n]
gradient
Change in y /change in x
Equation of line
y-y1 =m(X-x1)
quadratic formula
X= [-b+- root(b^2-4ac)]/2a
sine rule
a/sinA = b/sinB
OR
sinA/a =sinB/b
cosine rule
a^2 =b^2 + c^2 -2bc cos A
area of triangle
1/2 ab sinC
sin x =k 1st, 2nd and other solution
1st sin^-1
2nd 180-
other +- 350
cos X =k first second and other solution
1st cos-1
2nd 360 -
Other +- 360
tan x =k first second and other solution
1st tan^-1
2nd and other +- 180
tan x =
sin x/cos x
sin^2 x + cos^2 x =
1
sec x =
1/cos x
cosec x =
1/sin x
cot x =
1/tan x
cos x/sin x
cosec^2 x
1+ cot^2 x
sec^2 x =
1+ tan^2 x
sin 2x =
2sinxcosx
cos2x=
cos^2 x -sin^2 x
2cos^2 x -1
1- 2sin^2 x
tan 2x =
2tanx/(1- tan^2x)
arc length =
r@
sector area
1/2 r^2 @
Arthmetric nth term
Un= a + (n-1)d