Question

5 tan Φ = 4

maka
5 sun Φ - 3 cos Φ
_______________
5 sun Φ + 2 cos Φ

Answer 1

Tanx = sinx/cosx
cos x = √ 1 - sin²x

jadi, 4/5 = sinx/√ 1 - sin²x
√1 - sin²x=5/4 sin x
1-sin²x=25/16 sin²x
1=41/25 sin²x
sin²x=25/41, sin x=5/√41
cos²x = 16/41, cos x=4/√41
5*4/√41 - 3*5/√41
______________
5*4/√41 +2*5/√41
=20-15
_____
20+10
=5/30
=1/6