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Math Help - Finding values for expressions

  1. #1
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    Finding values for expressions

    Im asked to find these two values without using a table or calculator.

    1) Sin1.2(degrees)

    2) Tan 0.7(degrees)

    thank you for any help
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  2. #2
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    Quote Originally Posted by damonneedshelp View Post
    Im asked to find these two values without using a table or calculator.

    1) Sin1.2(degrees)

    2) Tan 0.7(degrees)

    thank you for any help
    Hello,

    if you have very small angles in radians you can use the property:

    sin(x) ≈ tan(x) ≈ x

    to 1): That means: Calculate the radians of 1.2 :

    x = 1.2/360 * pi = pi/150 ≈ 0.021 (you can guess this value using pi ≈ 3.14) Therefore you get:

    sin(1.2) ≈ 0.021

    to 2): Calculate the radians of 0.7:

    x = 0.7/3600 * pi (use pi ≈ 22/7) ≈ 22/3600 = 11/1800 ≈ 1/180 ≈ 0.006
    Therefore you get:

    tan(0.7) ≈ 0.006

    Please check my calculations with a calculator

    EB
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  3. #3
    Senior Member DivideBy0's Avatar
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    I got

    sin(1.2) = 0.020942419883...
    tan(0.7) = 0.12217912662...

    So the sin approximation seems about right, but the tan approximation is quite a bit off.
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  4. #4
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    Quote Originally Posted by DivideBy0 View Post
    I got

    sin(1.2) = 0.020942419883...
    tan(0.7) = 0.12217912662...

    So the sin approximation seems about right, but the tan approximation is quite a bit off.
    Hello,

    you calculated tan(7.0)

    EB
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