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Algebra2/trig please help?!?

1. In parallelagram ABCD, AD=8, AB=12, and diagonal BD=15. Find measure of angle BAD to the nearest degree?

2. If the roots of a quadriatic equation are -4+i and -4-i what could the equation be?

3. What is the exact value of sin (4(pie)/3) ?

4. Express (Cos(pie/3)) x (sin(3pie/4)) in simplest radical form?

5. Express tan(4pie/3) in terms of sine and cosine, then in simplest radical form?

6. Express tan(pie/6) in terms of sine and cosine, then in simplest radical form?

7. What are the exact coordinates that an angle with a measure of 2pie/3 radians meet a circle of radius 3?

8. What are the exact coordinates that an angle with a measure of 150 degrees meets a cirle of radius 12?

9. Find the area of a circle if an angle of 2pie/7 radians meets an arc of 12 centimeters?

10. Explain the difference between the "initial Side" of an angle and its "terminal side"?

11. If 1/2x+6=-x-3 what is the vlue of -2x?

Thanks guys

And PS i didn't just copy the homework onto this, these are questions from a entire review i didn't get.

2 Answers

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  • ­
    Lv 6
    1 decade ago
    Favorite Answer

    1) Use the law of Cosines...

    15² =12² + 8² -(12)(8)Cos(x)

    x = 79.8°

    2) This should use the Quadratic Formula. Here is a calculator for doing that...

    http://www.mathwarehouse.com/quadratic/quadratic-f...

    c = 8.5

    3) This uses the "exact angles" in trigonometry which need to be memorized. Here is a reference table for you to use when you have a problem like this...

    sin(4π/3) = -√(3)/2

    4) Again, you can use the table from question 3...

    -√(3)/4

    5) An identity of tanα is that it equals sinα/cosα

    So the trick is to see that...

    tan(4π/3) = sin(4π/3)/cos(4π/3)

    = √3

    6) tan(π/6) = sin(π/6)/cos(π/6)

    = (1/2) / (√3/2)

    = (1/2) * 2/√3

    = 2 / 2√3

    = 1/√3 = 1/√3 * √3/√3 = √3/3

    7) Use the rules of right angle triangles...

    Then x = √(9/5)

    Then y = 2x = 2√(9/5)

    8) See that 180° - 150° = 30°

    Then go from there...

    y² + 2y² = 12²

    y = 5.4, x=2*y = 2*(5.4) = 10.7

    9) There are 2π Radians in a Circle.

    A = 2*r²

    10) These definitions will help with this one and some of the others...

    http://www.sparknotes.com/math/precalc/trigonometr...

    11. x = -6

    Just multiply -2 by x which equals -6...

    -2x = -6*(-2)

    -2x = 12

  • Anonymous
    5 years ago

    complex problem. look at the search engines. that will help!

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