Matematika

Pertanyaan

diketahui tan A =2/3 (A sudut lancip). nilai dari sin 2A=....

2 Jawaban

  • tan A = y/x = 2/3
    x = 3
    y = 2
    r = √x² + y²
    r = √3² + 2²
    r = √9 + 4
    r = √13

    Sin A = y/r = 2/√13
                       = 2/13 √13

    Cos A = x/r = 3/√13
                         = 3/13 √13

    Sin 2A = 2 Sin A. Cos A
                 = 2 (2/13 √13)(3/13 √13)
                 = 156/169
                 = 12/13 

    semoga membantu dan jdikan jawaban terbaik ya
  • [tex] \tan (A) = \frac{2}{3} \\ \sin(A) = \frac{ 2}{ \sqrt{9 + 4} } = \frac{2}{\sqrt{13}} \\ \cos(A) = \frac{3}{\sqrt{9 + 4} } = \frac{3}{\sqrt{13}} \\ \\ \sin(2A) = 2 \sin(A) \cos(A) \\ = 2 \times \frac{2}{\sqrt{13}} \times \frac{3}{\sqrt{13}} \\ = \frac{12}{13} [/tex]

    Atau cara ini:
    [tex] \tan(A) = \frac{2}{3} \\ \frac{ \sin(A) }{ \cos(A) } = \frac{2}{3} \\ 3\sin(A) = 2\cos(A) \\ \\ \sin(2A) = 2 \sin(A) \cos(A) \\ = 3 { \sin }^{2} (A) \\ = 3( { \frac{2}{\sqrt{13}} )}^{2} \\ = 3( \frac{4}{13} ) \\ = \frac{12}{13} [/tex]

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