Question

Bantu nomer 3 dan 5 yaaa

Answer 1

Trigonometri

(3)

(tan 2x   - sin 2x) / (2 tan 2x)

= { sin 2x /cos 2x   - sin  2x ) / ( 2 sin 2x / cos 2x} . (kalikan cos 2x/cos 2x)

= ( sin 2x - sin 2x cos 2x ) /(2 sin 2x)

= { sin 2x ( 1 - cos 2x) / sin 2x (2)

= (1  - cos 2x) / (2)

= (1 -  (1 - 2 sin² x)) / (2)

=  (2 sin² x )/(2)

= sin² x

**

(5)  dari gambar

cos θ=  7/8

cos (θ+θ) =  7/x

2 cos²θ - 1 = 7/x

2 (7/8)² - 1 = 7/x

2(49/64) - 1 = 7/x

49/32 - 1 = 7/x

(49 - 32)/32 = 7/x

17/32  =  7/x

x = 7 (32)/(17)

x= 13,18