# SAT Math 2 subject test

## 62 terms

### Pith thing for factors/multiples

Factors are few. Multiples are many.

A=sum/#

### Repeated percent increase formula

Final amount = original (1+ Rate) ⁿ =original (1+ Rate) ^ (number of changes)

### Repeated percent decrease formula

Final amount = original (1- Rate) ⁿ =original (1- Rate) ^ (number of changes)

### Definition of a logarithim

logbN= x <--> b^x= N

logbA= logA/logB

### work done formula

work done= rate of work *time

A=(s²√3) / 4

### Area of a triangle formula (two)

A=1/2bh= 1/2absinθ

A=bh=absinθ

### Area of a square

A=s²= d²/2 (diagonal)

### Area of a trapezoid

A= average of basesheight= (b₁b₂/2)h

S=(n-2)180°

### Inscribed angle is...

1/2 the central angle

a²+b²+c²=d²

### The face diagonal of a cube is

face diagonal= s√2

### The long diagonal of a cube is

long diagonal= s√3

Vprism=Bh

Vcylinder=Πr²

### Surface area of a cylinder?

SAcylinder= 2Πr² + 2Πrh= 2Πr² +ΠDh=2Πr² +Ch

Vcone= 1/3Πr²h

### Surface area of a cone (include the base)

SA= ΠrL *Πr² (L=slant height/slanted side of the cone)

Vpyramind=1/3Bh

### Geometry question about the volume of a solid of all lengths are increased...

When lengths of a solid increase by certain factor, surface area increase by square of that factor, and volume increases by cube of that factor.

### distance formula

d=√(x₂-x₁)² + (y₂-y₁)²

### Standard formula for equation of a circle

(x-h)² + (y-k)²= r²

### Equation for a horizontal ellipse

(x-h)² /a² + (y-k)²/b² = 1 a>b (the larger under the x)

### Equation for a vertical ellipse

(x-h)² /b² + (y-k)²/a² = 1 a>b (the larger under the y)

### Major axis, minor axis, distance btw. focis for ellipse?

Maj axis=2A, Min axis= 2B, distance btw foci= 2c

### Equation for a horizontal hyperbola

(x-h)² /a² - (y-k)²/b² = 1 (y is negative=horizontal)

### Equation for a vertical hyperbola

(y-k)²/b² - (x-h)² /a² = 1 (x is negative= vertical)

### distance in a 3d space?

d=√(x₂-x₁)² + (y₂-y₁)² + (z₂-z₁)²

sin²x+cos²x=1

1+tan²x=sec²x

1+cot²x=csc²x

cscx

sec x

cot x

sin2x= 2sinxcosx

### cos2x=?

cos2x= cos²x-sin²x=1-2sin²x=2cos²x-1

### tan2x=?

tan 2x= 2tanx / (1-tan²x)

### sin (A+B)=?

sin (A+B)= sinAcosB +cosAsinB

### cos (A+B)=?

cos (A+B)= cosAcosB - sinAsinB (notice opposite sign)

### Finding amplitude/period

amplitude=a, period= 360/b or 2Π/b when y=asinbx

### Use law of sines when

S-S-A opp (two sides and one of their opposite angles) or A-A-Sany (two angles and any side)
(ASS or AAS)

### Use law of cosines when

S-S-S (all three sides) or S-A-S (two sides and angle between them)
(SSS or SAS)

### Converting from rectangular to polar

x²+y²=r² and tanθ=y/x

x=rcosθ y=rsinθ

### To find inverse function

1. Rewrite f(x) as y 2. switch y's and x's 3. solve for new y

### Even function

f(-x)=f(x) y-axis symmetry. (think x=y, -x=y)

### Odd function

f(-x)= - f(x) origin symmetry (think x=y, -x= -y)

### Degree of polynomial tells us..

the maximum amount of zeroes/roots, and (n-1) is the number of extremas or min/max

### Number of standard deviations above/below?

Mean-number/Standard deviation= # (of SDs)

order matters

### Combination

order does not matter (like choosing groups/committees)

### Group problem

Total= Group 1+ Group 2 + Neither - Both

an=a₁ +r(n-1)

### Sum of the first n terms of an arithmetic sequence

Sum arith= n (a₁ + an/2) = number of terms *average of 1st and An

an= a₁ * r ⁿ⁻¹

### Sum of first n terms of a geometric sequence

sum geo= a₁ (1- r ⁿ)/ 1-r

sum geo= a₁/ 1-r

### You can only multiply matrices if the first matrix has the same number of columns as the second matrix has..

rows. (1st matrix columns=2nd matrix rows)