Question

Diketahui cos a = k, hitunglah
1) sin (90° - a)
2) tan (90° - a)
3) cos (90° - a)​

Answer 1

Verified answer

Penjelasan dengan langkah-langkah:

cos a = k

cari sin a

= √(1 - cos²a)

= √(1 - k²)

a) sin (90° - a)

= cos a

= k

b) tan (90° - a)

= cot a

= cos a/sin a

= k/√(1 - k²) → rasionalkan

= k/√(1 - k²) . √(1 - k²)/√(1 - k²)

= k . √(1 - k²)/1 - k²

= (k√(1 - k²)/(1 - k²)

c) cos (90° - a)

= sin a

= √(1 - k²)