Question

Buktikan bahwa:
sin (A + B) tan A + tan B
--------------- = ----------------------
cos (A - B) 1 + tan A tan B

Answer 1

Verified answer

Bab Trigonometri
Matematika SMA Kelas X

(sin (a + b)) / (cos (a - b))
= (sin a cos b + cos a sin b) / (cos a cos b + sin a sin b)
= (cos a cos b (sin a/cos a + sin b/cos b)) / (cos a cos b (1 + ((sin a sin b)/(cos a cos b)))

**coret cos a cos b**

= (sin a/cos a + sin b/cos b) / (1 + ((sin a sin b)/(cos a cos b)))
= (tan a + tan b) / (1 + tan a tan b)

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