diketahui sin a 4 per 5 dan cos b 12 per 13 hitunglah a sin a (a tambah b) b.sin (a kurang b) c.cos (a tambah b) d.cos (a kurang b)e.tan (a tambah b) f.tan(a kurang b)…..tolong ya dengan caranya..

Dik : sin a = 4/5 , cos b = 12/13 , cari sin b dan cos pake rumus phytagoras ( sin b = 5/13 , cos a = 3/5 , tan a = 4/3 , tab b = 5/12
jawab:
a. sin(a+b) = (sin a x cos b) + (cos a x sin b) = (4/5 x 12/13) + ( 3/5 x 5/13) = 48/65 + 15/65 = 63/65
b.sin(a-b) = (sin a x cos b) – ( cos a x sin b) = (4/5 x 12/13) – (3/5 x 5/13) = 48/65 – 15/65 = 33/65
c. cos(a+b) = (cos a x cos b) – (sin a x sin b) = ( 3/5 x 12/13) – (4/5 x 5/13) = 36/65 – 20/65 = 16/65
d. cos(a-b) = (cos a x cos b) + (sin a x sin b) = (3/5 x 12/13) + (4/5 x 5/13) = 36/65 + 20/65 = 56/65
e. tan(a+b) = (tan a + tan b) : (1 – tan a x tan b) = (4/3 + 5/12) : (1 – 4/3 x 5/12) = 63/16
f. tan(a-b) = (tan a – tan b) : (1 + tan a x tan b)= (4/3 + 5/12) : (1 + 4/3 x 5/12) = 9/8

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