Dik: tan a=1/2 dan tan b=1/3. dit nilai dari tan (a – 2b)

tan 2b

= (2 . tan b) / (1 – tan² b)

= (2 . 1/3) / (1 – (1/3)²)

= (2/3) / (9/9 – 1/9)

= (2/3) / (8/9)

= 2/3 . 9/8

= 2/8 . 9/3

= 1/4 . 3

= 3/4

………………………………….

tan (a – 2b)

= (tan a – tan 2b) / (1 + tan a . tan 2b)

= (1/2 – 3/4) / (1 + 1/2 . 3/4)

= (2/4 – 3/4) / (1 + 3/8)

= (-1/4) / (11/8)

= -1/4 . 8/11

= -8/4 . 1/11

= -2/11

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Kelas 10

Pelajaran Matematika

Bab 6 Trigonometri Dasar

Kata kunci : –

Kode kategorisasi : 10.2.6