Jika diketahui sin alpa=1/√5 dan sin beta =1/√10. Maka tentukan : a. Tan(alpa-beta) b. Sin (alpa+beta) Tolong jwab ya ,makasih

sin a = 1/√5
sisi depan = 1
sisi miring = √5
sisi samping = 2
cos a = 2/√5
tan a = 1/2
sin b = 1/√10
sisi depan = 1
sisi miring = √10
sisi samping = 3
cos b = 3/√10
tan b = 1/3

a) tan (a+b) = (tan a + tan b)/(1 - tan a tan b)
= (½ - ⅓) / (1 - (½)(⅓))
= (3/6 - 2/6) / (6/6 - 1/6)
= (1/6) / (5/6)
= 1/6 × 6/5
= 1/5
b) sin (a+b) = sin a cos b + cos a sin b
= (1/√5)(3/√10) + (2/√5)(1/√10)
= 3/√15 + 2/√15
= 5/√15
= 5√15 / 15
= ⅓√15