Anonymous
Anonymous asked in Science & MathematicsPhysics · 1 month ago

What is the value of A (physics)?

Can someone please help for physics? I have an exam next week and my professor is not teaching the material:(

What is the value of A if sin(39.2)=cos(A)

Thanks:)

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  • 1 month ago
    Favorite Answer

    sin(39.2) = cos(A)

    sin(39.2) = sin(A + 90)

    (39.2) = (A + 90)

    A = 50.8

    www.physicstutorialroom.com

    • Vaman
      Lv 7
      3 weeks agoReport

      DId you miss the negative sign when subtracting?

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  • 1 month ago

    You can use a calculator to do this. Find the sine of 39.2° and then using the same calculator find the arcos of that. You will find that

    A = 90°-39.2° = 50.8° since sin(Θ) = cos(90-Θ)

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  • 1 month ago

    sin 39.2° = 0.632029303

    cos A = 0.632029303

    A = arccos 0.632029

    A = 50.8 °

  • Vaman
    Lv 7
    1 month ago

    cos a=sin 39.2= cos (39.2-90)

    a= 39.2-90=-50.8

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  • Anonymous
    1 month ago

    the easier way :

    sin 39.20° = 0.6320

    0.6320 = cos A

    A = arccos 0.6320 = 50.80°

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  • 1 month ago

    The most straightforward way of remembering things like this is to recall that these functions are all ratios involved in right triangles.

    Sine = Opposite/Hypotenuse

    Cosine = Adjacent/Hypotenuse.

    Which means that for any given right triangle, where A and B are the two angles aside from the right angle, Sin(A) = Cos(B)

    Also, since we know that the sum of all the internal angles of any triangle = 180 degrees, we know that the sum of A and B must be 90 degrees in a right triangle.  In other words, they are complementary angles.

    Combining all that previous knowledge together, we get Sin(A) = Cos(90-A).  The Sine of any acute angle is the Cosine of its complementary angle.

    Plugging your numbers into it, we get:

    Sin(39.2) = Cos(90-39.2)

    So the value of your answer is 90-39.2 = 50.8

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  • Lôn
    Lv 7
    1 month ago

    Easy.... it's 90 - 39.2 = 50.8.

    sin (39.2) = 0.6320

    cos (50.8) = 0.6320

  • 1 month ago

    sin(39.2)=cos(A)

    cosA = 0.6320293

    A = 50.8º

    • ...Show all comments
    • JOHN
      Lv 7
      1 month agoReport

       In this way unique inverses have been defined for inverses of the periodic functions.

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