Sunday, April 11, 2010

Stephen's reflection

Ok so yea i dont want school tomorrow and i forgot a bunch of stuff sooo yea..anyway i will talk about some trig stuff like SOHCAHTOA, law of sines and law of cosines..these are the formulas you use and the rest is reallllyyyy easy soooo yea.

SOHCAHTOA
sinΘ=opposite leg/hypotenuse
cosΘ=adjacent leg/hypotenuse
tanΘ=opposite leg/adjacent leg

Law of Sines
sinA/a - sinB/b = sinC/c
(used when you know pairs or opposites in a non-right triangle)

Law of Cosines
(opposite leg)²=(adjacent leg)² + (other leg)² - 2(adjacent leg)(adjacent leg)cos°

Ok so what i dont really remember is i can use help on limits and sigma notation..i forgot all that stuff

1 comment:

  1. there are two types of limit equations
    the ones that use rules and the ones that use a calculator

    the ones that use rules have simple hints to memorize for solving
    the only ones that use rules are the polynomial equations problems

    memorize this

    ((the rules))
    t- top lead co
    b- bottom lead co

    t=b then coefficients
    t>b then infinity
    t
    if you get a problem with a limit that is a polynomial equation
    use the rules.
    each and every time

    the other type of problem is the one that calls for the use of a calculator
    every single problem with limits that is not a polynommial equation calls for the use of a calculator

    all you have to do is plug in for n three different times with
    100
    1000
    10000
    then plug into calculator
    record what each outcome is and decipher what the numbers are headed toward which will then be your answer





    Sigma has three parts
    A top number
    A middle number
    A bottom number

    Top is called limit of summation
    Middle is called the summand
    Bottom is called index

    Top is the address of the last number in given series
    Middle is the result of the tn formula
    Bottom is what number you start counting at

    If the equation is arithmetic then the bottom number will be 1
    If the equation is geometric then the bottom number will be 0

    When asked to evaluate for a sigma problem you plug in the numbers including and between the bottom and the top numbers
    So if the bottom number is one and the top number is five then you would plug in 1,2,3,4,5 for the variable of the middle equation and add the results of each plug in togethe3r to get the final answer


    When asked to express then you draw the sigma sign and fill in the top middle and bottom parts

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