tolong yaaa dari nomor 11 samapi 14 :) terimah kasih:)

11.
sin A = 12/13
180° <_ A <_ 270° (KUADRAN III)

r = 13
y = 12
x^2 = r^2 - y^2
= 13^2 - 12^2
= 169 - 144
= 25
x = akar 25
x = 5

tan A = y/x
= 12/5
jadi nilai tan A adalah 12/5 (tan di kuadran III bernilai positif) (d)
12.
sin A = 3/5
r = 5
y = 3
x^2 = r^2 - y^2
= 5^2 - 3^2
= 25 - 9
= 16
x = akar 16
x = 4
cotan A = x/y
= 4/3
jadi cotan A adalah 4/3 (e)
13.
sin 60° = 1/2 akar 3
tan 60° = akar 3
sin 45° = 1/2 akar 2
cos 45° = 1/2 akar 2
sin 60°.tan 60° + sin 45°.cos 45°
= (1/2 akar 3)(akar 3) + (1/2 akar 2)(1/2 akar 2)
= (1/2 × 3) + (1/4 × 2)
= 3/2 + 2/4
= 6/4 + 2/4
= 8/4
= 2
(e) (soal salah => Nilai sin sin 60° ......harusnya
Nilai sin 60° .......)
14)
sin 30° = 1/2
cos 60° = 1/2
sin 45° = 1/2 akar 2
cos 30° = 1/2 akar 3

sin 30° + cos 60°
-------------------------- =
sin 45° + cos 30°
..........1/2 + 1/2
--------------------------------- =
1/2 akar 2 + 1/2 akar 3
................1
---------------------------- =
1/2(akar 2 + akar 3)
............2
---------------------- =
akar 2 + akar 3
...........2 (akar 2 - akar 3)
----------------------------------------------- =
(akar 2 + akar 3)(akar 2 - akar 3)

2(akar 2 - akar 3)
-------------------------- =
...........2 - 3

2(akar 2 - akar 3)
-------------------------- =
...............-1

= -2(akar 2 - akar 3) (....)