Other formulas Flashcards
1
Q
Quadratic formula
A
(-b ±√b²-4ac) / 2a
2
Q
Direct proportionality
A
x=ky
3
Q
Inverse proportionality
A
x=k/y
4
Q
Simple interest
A
I= PRT/100
5
Q
Compound interest
A
A= P (1+ “R/100” )^n
6
Q
Equation of a line
A
y=mx+c
7
Q
Gradient of a line
A
y2-y1 / x2-x1
8
Q
Midpoint of two given points
A
( (x1+x1)/2 ), ( (y1+y2)/2 )
9
Q
Distance between two given points
A
√ (x1-x2)² + (y1-y2)²
10
Q
Total of exterior angles in a polygon
A
360
11
Q
Total of interior angles in a polygon
A
180 (n-2)
12
Q
To find an exterior angle in a polygon
A
360/ n
n= no. of sides
13
Q
To find an interior angle in a polygon
A
180- exterior angle
14
Q
The sine rule
A
a/Sin A = b/Sin B = c/Sin C
15
Q
The cosine rule
A
a²= b²+c² - 2bc COS A
16
Q
The area of a triangle
A
1/2 ab sinC
17
Q
Frequency density
A
Frequency/Class width
18
Q
Magnitude in vectors
A
√x²+y²
