Matematika

Pertanyaan

(sin 15 +cos 15)(sin 15 - cos15) = ?

1 Jawaban

  • (a + b)(a - b)
    = a² - b²

    jadi
    (sin 15 +cos 15)(sin 15 - cos15)
    = sin
    ²15 - cos²15
    = -(cos²15 - sin²15)
    = -cos(2.15)
    = -cos30
    = -(1/2)√3

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