What math formulas should I memorize if my math section goal score is 25-27?
Distance Formula d=√(x₁-x₂)² + (y₁-y₂)²
(EX: Find distance between (5,6) and (1,3)
√(5-1)² + (6-3)²=
√(4)² + (3)²=
√16 + 9=
√25=
5=Distance
Slope Slope= Rise/Run=Change in Y/Change in X
(y₂-y₁/x₁-x₂)
(EX: Find slope of (5,6) and (1,3)
6-3/5-(-1)=
3/6=
1/2
Slope Intercept y=mx+b
Ex: y=2/3x + 5
Midpoint Formula (x₁+x₂)/2, (y₁+y₂)/2
PEDMAS Parenthesis, Exponents, Multiplication, Division, Add, Subtract.
EX: 9-2 x (5-3)² + 6÷3=
9-2 x (2)² + 6÷3=
9-2 x (4) +6÷3=
9-8 +2=
9-6=
3
Quadratic Equation ax²+bx+c= 0
EX: x²+ 9x+ 18=0
Quadratic Formula ²x = −b ± √b²-4ac/2a
EX: Solve using quadratic formula x²+ 9x+ 18=0:
x= −9±√(9)² − 4(1)(18)/2(1)
−9 ± √81 − 72/2
−9 ± √9/2
−9 ± √3/2 = -9 + 3/2 and -9 -3/2
-9+3/2= -3 and -9-3/2= -6
Percent Formula Part=Percent x Whole
Multiply Power Exponents add exponents and keep the same base
EX: X₃ · X₂ = X₅
Dividing Power Exponents subtract exponents and keep same base
EX: X₄ ÷ X₂ = X₂
Raising Power to Powers multiply the exponents
EX: X² · X³ = X⁶
Negative Exponent X⁻ⁿ = 1/Xⁿ
Rational Exponent ⁿ√x
Absolute Value |-3| = 3
FOIL First, Outside, Inside and Last.
EX: (x-3) + (x+5) =
x² + 5x -3x -15=
x² + 2x-15
Factoring Difference of squares a²-b² = (a-b) (a+b)
Area of a Triangle area= ½ (base)(height)
Pythagorean Theorem for all right triangles
(leg₁)² + (leg₂)² = (hypotenuse)² (a²+b²=c²)
Special Triangles
3-4-5
30-60-90
5-12-13
45-45-90
Area of rectangle area= length x width
Area of parallelogram area= base x height
Area of square area = (side)²
Circumference of a circle area = 2πr
Area of a circle πr²
The ACT includes a little trig so it might not hurt knowing the basic trig rules and identities (incl. definitions, sum/difference formulas, law of sines, law of cosines).