I’m taking the ACT tomorrow and usually I end up with numbers in the 30s on every section except the math (sigh). My biggest problem is the geometry. I have a Barron’s book, but are there any other good resources to study by/certain formulas/concepts I should memorize? Thanks!
I found this formula fact thing from SAT Math Facts and Formulas
anyways I’ll write some of the stuff (it’ll help me remember too! lol)
Lines: know the parallel lines angles (like vertical lines are equal in degrees)
Triangles: know the a^2+b^2=c^3 (I’m sure you already do), also x, 2x, x√ 3 triangles and x,x, x √ 2
3-4-5 triangles, (5, 12, 13), (8, 15, 17)
Area = 1/2 b * h
Trig:
sin= opp/hyp cos= adj/hyp tan=opp/adj (SohCahToa)
Factoring, Solving:
FOIL, Difference of Squares, Reverse FOIL
Functions:
f(x) g(x) stuff (def go over this if u dont know it, its easy and it’ll get you atleast one answer right)
Logarithms:
remember log xy= log x + log y
know how to solve y = log x
Complex numbers:
the i’s, so i^0= 1, i^1=i, i^2=-1… etc
this is on your calculator!!
Lines:
DISTANCE, MID POINT, SLOPE (u need to know this!!!)
Circles:
area= pi r ^2
circumference= 2 pi r
full circle = 360 degrees
length of arc = degrees / 360 * 2 pi r
area of sector = degrees / 360 * pi r^2
equation of circle (x-h)^2 + (y-k)^2 = r^2
converting from degrees to radians multiply pi/180 degrees.
rectangle (area)
parallelogram (area = l*h)
trapezoid area
(base1 + base2 / 2) * h
Arithmetic sequences:
t1, t1+x, t1+2x, t1+3x, etc…
geometric sequence
t1, t1r, t1r^2, t1r^3, t1r^4, etc…
^^ IMPORTANT TO KNOW
Percents
part = percent/100 x whole
^^ ALSO IMPORTANT TO KNOW
example,
75% of 300 is what?
(75/100) x 300 = ??? (225)
know average, sum, mode (what appears most often), median (middle value)