trigonometry (MathMate)

posted by .

MathMate i would really appreciate
if you can show me where the logarithms can be used.I know they are unnecessary and I already found the answer without them but i still have to show my work using logarithms and they just confuse me. I also have most trouble woth the anti-logarithm.
I am seriously frustrated so you help would be appreciate.
I hope my repost is okay because i wasn't sure if you would go back and check the older post.

Find the area of the following triangles:(use logarithms)

1) c=426, A=45degrees 48' 36",and B=61degrees 2' 13"

  • trigonometry (MathMate) -

    It is perfectly to repost with a reference to an earlier post.

    Here it is:

    Given triangle,
    A=45-48-36
    B=61-02-13
    c=426
    C=180-00-00 - (45-48-36 + 61-02-13) = 73-09-11

    Solve by the sine rule:
    a/sin(A)=c/sin(C)
    a=c*sin(A)/sin(C)

    value logarithm
    c 2.6294096
    sin(A) 1̅.8555387
    c*sin(A) 2.4849483 [ADD]
    sin(C) 1̅.9809493
    a 2.5039990 [SUBTRACT]
    Anti-log 319.1530 (length of c)

    Now proceed to calculate area:

    Area = (1/2)a*c*sin(B)

    value logarithm
    (1/2) 1̅.6989700
    a 2.5039990
    c 2.6294096
    sin(B) 1̅.9419744
    Area 4.774353 [ADD]
    Anti-log 59477.54


    Note:

    when a number is between 1 and 10, it is normalized, and the logarithm (to the base 10) is between 0 and 1.
    Example: log(2) = 0.30103

    However, when the number is less than 1, such as 0.5, the decimal is moved one place to the left, and log(5) is recorded (.6989700) with a 1̅ to the left meaning the decimal has been move one to the left.

    Conversely, the logarithm of 50 is written simply as 1.6989700, meaning log(5) with one decimal placed to the right.

    If you need more details, post (here).

  • trigonometry (MathMate) -

    okay i was able to get
    c*sin(A)= 1.8555387
    but i was lost after that. I couldn't reproduce the same answers u have.

    value logarithm
    c 2.6294096
    sin(A) 1̅.8555387
    2.4849483 [ADD]
    sin(C) 1̅.9809493
    a 2.5039990 [SUBTRACT]
    Anti-log 319.1530 (length of c)

  • trigonometry (MathMate) -

    Are you able to get the individual logarithms?

    For example,
    A=45.81°
    sin(A)=0.7170323
    sin(A)*10=7.170323 (normalize number to between 1 and 10)
    Log(sin(A)*10)=0.855387
    To move the decimal back one place to the left, we put a (-1) denoted by 1̅ which makes
    log(sin(A))=1̅.855387

    The we add (instead of multiply) the logarithms
    c 2.6294096
    sin(A) 1̅.8555387
    2.4849483 [ADD]

    which is
    2.6294096+(-1)+.855387
    =2.4849483
    Note that the mantissa (the decimal part of the log) is always positive. The characteristics (integer part) are always added separately, and do remember to add the carries, if any.

    The subtraction would be calculated similarly.

    Please post again if you need more details.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. mathmate

    hey mathmate i am having trouble with accounting do you know if you could help me out
  2. trigonometry

    okay so i have this trigonometry problem were i HAVE to use logarithms. Now this is my work but can u help me solve it using logarithms. Find the area of the following triangles:(use logarithms) 1) c=426, A=45degrees 48' 36",and B=61degrees …
  3. trigonometry

    1. Finde the area of the following tringles: (use Logarithms) A) a=12.7, b=21.5, c=28.6. i'm not of the answer i got. i got 127.6 if you got something different can you show me how you did while using logarithms.
  4. Trigonometry (Logarthims)

    Give checks to the following two questions Use logarithms and the law of tangents to solve the triangle ABC, given that a=21.46 ft, b=46.28 ft, and C=32°28'30" without logarithms i can do this problem easily and i have. but when i …
  5. trigonometry

    Use logarithms and the law of tangents to solve the triangle ABC, given that a=21.46 ft, b=46.28 ft, and C=32°28'30" Also Give checks. I know the use of logarithms is unnecessary but i have to show my solution by using logarithms …
  6. trigonometry (repost) Mathmate

    I want to start by saying thank you . You have no idea how much u have helped me understand logarithms, even better then the books i have (it poorly explains the subject of trigonometry let alone logarithms and antilog). Your last …
  7. trigonometry (repost) Mathmate

    Use logarithms and the law of tangents to solve the triangle ABC, given that a=21.46 ft, b=46.28 ft, and C=32°28'30" Using the previous values, a=21.46 b=46.28 C=32-28-30=32.475 We have A+B=180-32.475=147.525 a+b=67.74 a-b=-24.82 …
  8. kahyla

    use the properties of logarithms to write the expression as a sum or difference of logarithms or multiples of logarithms. show your work Ln 8x 2. log2y^5
  9. calculus

    use the properties of logarithms to condense the logarithmic expression. write the expression as a single logarithms whose coeffient is 1. Inx+In5=?
  10. AB Calculus

    Assume that x, y, z and b are positive numbers. Use the properties of logarithms to write the expression logb 4(square root)x^7y^2 / z^4 in terms of the logarithms of x, y and z a. 28logbx+8logby-16logbz b. 7/4 logbx+1/2 logby-logbz …

More Similar Questions