Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
SAT stuff
| Question | Answer |
|---|---|
| What is the mean? | its the same thing as the average |
| median | put the numbers in order, pick the middle: if there are two middle numbers, then find the average of these two numbers |
| mode | the number that appears most often |
| How to know if sm is a quadratic function given a table of x and y values | 1. Find the first differences (subtract the y values) 2. Find the second differences and if the 2nd difference is constant (the same number over and over) it is a quadratic → on a graph they make a U or upside down U shape |
| quadratic function formula | y = a(x-h)^2 + k vertex= (h, k) -PARABOLA |
| natural numbers | numbers you can count w/ (excludes zero) |
| whole numbers | natural numbers + zero |
| Integers | whole numbers + negatives |
| Rational numbers | numbers that can be written as a/b (repeating decimals count) |
| irrational numbers | cannot be written as a fraction, decimals that go on forever without repeating |
| factoring out a common binomial | 57x(x+b) + a (x + b)=0, factor out x+b → (x+b)(57x+a)=0 |
| formula of a circle | (x - h)² + (y - k)² = r² (h,k): The coordinates of the circle's center. (r): The radius (distance from the center to any point on the edge). |
| completing the square | X^2 + 6x +3 = 9 → X^2 + 6x + __ + 3 - 9 = 0 _____ = (6/2)^2 = 9 X^2 + 6x + 9 + 3 - 9 (x+3)^2 - 6 6 = (x+3)^2 +or- rad6 = x+3 |
| when to put the plus or minus symbol in front of your answer | x^2 = A x = + or - radA |
| Given two points, how to find the y-intercept | find the slope and then use point-slope form OR you can use y-intercept form by plugging the m and one point into the equation y = mx +b |
| compound interest. | A = P (1 + r/n)^nt → A = final amount, P = principle amount, r = annual interest rate (decimal) n = number of times compounded per year, t = yrs -you earn interest on the original money and on the interest you've already earned |
| Continuous compounding | A = Pe^rt -instead of interest being added yearly monthly, or daily, it's constantly added every instant -growth happens continuously |
| Simple interest | I = Prt → interest earned, → Total amount = A = P + I -you earn interest only on the original amount, you increase by the same amount each time |
| Percent growth | A = P (1 + r)^t |
| Percent Decay | P(1-r)^t |
| Exponential models | y = a(b)^x → a = starting value, b>1: growth, 0 < b< 1: decay x = time or number of periods (how many times the growth or decay happens) |
| Present value | PV = FV/[(1+r)^n] -present value = amount of $ needed today to end w/ a certain amount in the future -FV = future value r = interest rate per period n= # of periods -anything that changes by the same percent or same multiplier each period |
| Distance formula | rad[(x-x)^2+(y-y)^2] |
| midpoint | [ (x + x)/2, (y+y)/2] |
| quadratic formula | x = -b +or- rad(b^2 - 4ac) all divided by 2a |
| Vertex formula | b/2a |
| Vieta’s formula | if you have a quadratic equation in standard form (ax^2 + bx +c = 0), then the sum of the solutions is -b/a and the product of the solutions is c/a |
| When given two expressions that equal each other, sometimes you move everything to one side and set equal to zero, and sometimes you simply each side individually. | Move to one side→ solving for x or y, Simplify separately → two expressions are equivalent and ask for a constant like r, a, or k |
| -given an absolute value equation | |a+x| = c and |a+x| = -c |
| Discriminant > 0 | two solutions |
| Discriminant < 0 | no real solutions |
| Discriminant = 0 | one solution |
| FOIL | first, outside, inside, last (a+b)(c+d) → a * c, a*d, b*c, b*d |
| If an equation is linear... | -both the x and y variable an exponent of 1 and that x and y are not multiplied together -it can be written as a line on a graph |
| given a function, f(x) and y are the same thing, so when asked to find when f(x) is 0 | find where the graph intersects the x-axis (AKA when y = 0) -also, these points are the roots, zeros, or solutions |
Created by:
Blessed Rectangle 11