Math Flashcards
What is an acute angle
lesss than 90 degrees
what is a right angle
90 degrees
what is an obtuse angle
more than 90 degrees
what is a straight angle
180 degrees
what is a supplementary angle
a + b = 180 degrees
what is a complementary angle
x + y = 90 degrees
What is a bisected angle
2g = h degrees
what is the formula for circumference of a circle
2pier or pie*d
what is the formula for area of a circle
pie*r^2
what is the formula for arc length of a of an arc
xdegrees/360(2pier)
what is the formula for sector perimeter of a arc
2r+x/360(2pier)
what is the formula for sector area of a arc
x/360(pie*r^2)
what does tangent mean
perpendicular to something
what is the formula for an arithmetic sequence
an=a1+d(common difference) *(n-1)
how do you find the nth term of a geometric sequence
dividing any term by the term before it gets you the ration
How do you find the nth term of a repeating sequence
Figure out how many numbers it repeats for
Find the remainder of the number you’re trying to find/ the number of how long it repeats for
find the term that corresponds to the remainder
volume of a rectangle
lwh
surface area of a rectangle
2lh+2lw+2*hw
Volume of a cylinder
pier^2h
How do you, generally, find the surface area of a 3d shape
sum of areas of all the faces
volume of a circular cone
1/3pieh*r^2How
how do you find a diagonal of a 3d shape
USE THE PYTHAGOREAN THEOREM. map it out in your head.
How do I find the numbers for a ration given like 2:3
2/3 = x/given # and cross multiply.
what is the rule for a triangle
the two sides, x and y, the third side must be less than x+y but greater than x-y
what is the difference of cubes
(a-b)(a^2+ab+b^2)
solve this log3 1/81 = what steps do you take
what power do you raise 3 to get 1/81
-4
How do you multiply a matrice
to get the top left number of the resultant matrice you would multiply the each number of the first row by each number of the first column and adding those numbers together
what are the restrictives for wether or not you can multioply a matricy and what does the dimension of when you do multiply
You can only multiply. matrice with dimensions that have the same inner number. 2x3 and 3x4 the resulting matrice is a 2x4, the outer dimensions
how do you find the determinant of a matrice
ad - bc
How do you find the expected value of an event / y
value of event * probability of event occuring and adding all of those together depending on how many events you have
when do you choose a combination combinatoric
chosen when the role order doesn’t matter 2 vs 1 and 1 vs 2 are the same thing
when do you choose a permutation combinatoric
chosen when the role order does matter. 2 vs 1 and 1 vs 2 are different values
what is the mean and how do you calculate it
the average
the sum divided by the number of values you have
how do you calculate the median and what is it
the middle number ordered in least to greatest
how do you calculate the mode and what is it
it is the number that occurs most frequently. you can sometimes have no mode if there are the same numver of frequencies
how do you calculate the weighted average
multiply the average by its weight all added together to get the total average.
what is an isosceles triangle
Two sides are equal therefore two angles are also equal
How can I re-write log4 x = 3 to solve for x?
4^3 = x
what does the equation of a circle equal?
the squared number of the radius
what is the man hours equation and what does it tell you
number of people * number of time = the man hours it takes. For example if we had 3 workers complete a house in 10 months, how long would it take for 5 people?
we multiply 3 by 10 = 30 and then multiply that by 1/5 to get the amount of time it will take for 5 people to build the same house
what is standard deviation
a measurement of how far accumulative data points are away from the mean
data points closest to the mean have a smaller standard deviation (2,2,3,3,4,4) while data points farther from the mean have a larger standard deviation (1,2,3,4,5)
If there is a perimiter, say 28, and the question asks you how to find the largest area, how do you do that, using formula based?
2l + 2w = 28
and solving for length, l = 14-w
A = lw so we can subsitute l in
A = 14-w*w
then we can find the vertex of the parabola, the middle x point, which gives us w so 7! that means the optimal area is 49
What is the formula to type for permutation and combinations
NPr
N= total objects
R=number of objects chosen at once
To find the interior angle sum of a polygon, we can use a formula
(n - 2) x 180 n meaning number of sides
from degrees to radians
degrees * by 180 over pie
from radians to degrees
radians times 180/pie
how do I know if it’s whom or who
whom = him
who = he
what is the law of cosines
C squared equals a squared plus b squared minus 2 ab cos gamma
what is the law of sins
sine alpa divided by A equals sin beta divided by b equals sin gamma divided by c
How can I solve for averages
An=s(total sum)
How do i add vectors
place each reactant on top of one end and connect the new shape
