Test 3 - Final Exam Flashcards
Test 3
Slope =
How to find the slope
Week 9
y2-y1/x2-x1
It is Minus NOT addition
Distance or d=
How to calculate the distance between two points
Square root of (x2-x1)^2 + (y2-Y1)^2
How to find the y-intercept and x-intercept of the line. (EQUATION)
To find the y-intercept, we set x=0 and the same for the x-intercept, we set y=0.
|-19| should be:
19
How to find the midpoint M of the line segment
Using the formula (x1+x2/2, y1+y2/2)
A vertical line means
undefined, while a horizintal line means zero
How to graph a line
First, we choose some x-values. Then, we evaluate the equation for each of the x-values.
e.q y=3x we will do the following: y=3(1)= (1,3)
Find an ordered pair (x,y) that is a solution to the equation.
There are infinitely many ordered pairs, To find one, we can choose a value for one of the variables and solve for the other variable. E.q x-5y=5 we can give x a value of 0 and be left with 5y=5. Thn, we solve y by diving 5 by 5 and we will get the following answer (0, 1)
How to find the equation of the line that is parallel and passes through a point
Week 10
We use the same slop of the equation and then change the y and x to the point that was provided
How to find the equation of the line that is perpendicular and passes through a point
We use a slope that give a result of -1 (e.q 9 will be -1/9).
IMPORTANT TO NOTE: when multiplying the slope with x and the result was a fraction e.q (7/11) you multiply x with 7, and y with 11 as well as giving it the denominator 11.
How to list each zero of f according to its multiplicity (multiplicity 1,2, and 3)
E.q multiplicity 2 means (x+5)^2 to find it zero means we do the following x+5=0 which equals x= -5
so, its zero is -5
What is the y-intercept
y=mx+b
If you were asked to graph, the points will look like this (0,b)
Joe is putting money into a checking account. Let y represent the total amount of money in the account (in dollars). Let x represent the number of weeks Joe has been adding money. Suppose that x and y are related by the equation y=550+20x.
1. What is the change per week in the amount of money in the account?
2. What was the starting amount of money in the account?
- the answer will be the slope which is 20
- the answer will be the y-intercept which is 550
How to find the decond point on the line after finding the y-intercept e.q y=5x+3 will be (0,3)
To fnd the second point, we will use the slope e.q 5. The rise (y) is 5 and the run (x) is 1 so we will take the first point we got from the y-intercept (0,3) and add (0+1, 5+3) = (1, 8). The answer or the second point will be (1,8)
How to solve the following: The credit remaining on a phone card (in dollars) is a linear function of the total calling time made with the card (in minutes). The remaining credit after 44 minutes of calls is $18.84, and the remaining credit after 73 minutes of calls is $14.78. What is the remaining credit after 93 minutes of calls?
We subtract 73 from 44 = 29 m
$18.84 - $14.78 = $4.06
IF we are looking to find the dollars we will divide them with 29. they will look like this 4.06/29 and the opposite if we want to find the minutes e.q 29/4.06
After dividing we get 0.14.
To find the remaining credit after 93 we subtract it from 73 (depend on the number) we get 20.
we multiply 20 by 0.14 = 2.8 then we subtract (or add, depends if it was increase or decrease) 14.78-2.8=11.93
Answer: 11.93
How to draw a graph to help solve the equation. Then find the solution to the equation.
First, if the equation was 3x=-3 we will move the -3 to the other side so it can give use the following order: y=mx+b
After, we give x a value and start graphing
Then, we look at the graph to 0 and see where the point will be based on the line and this will be the x sloution
How to find all the zeros of the quadratic function. e.q x^2+9x+20
We solve (or simplify) the quation x^2+9x+20
so it will be (x+4)(x+5)
The zeros wil be: -4,-5
How to choose the statement that best describes how (something) and (something) are related based on the graph given, and how to give the requested value.
We look at the point if the point on y is 45 and x is 0 and the next point in y is 35 and x is 1then we will subtract 45 from 35 (based on the graph we will know if it was an increase ADD or decrease SUBTRACT) The answer will be 10
What is the ratio for a Direct variation
k= y/x
equation will be y=kx
What is the ratio for an Inverse variation
k=xy
equation will be y=k/x