Question

How do I solve this?​

Answer 1

Step-by-step explanation:

(i) Use law of cosine:

c² = a² + b² − 2ab cos C

c² = (√3 − 1)² + (√3 + 1)² − 2(√3 − 1)(√3 + 1) cos 60°

c² = 3 − 2√3 + 1 + 3 + 2√3 + 1 − 2(3 − 1) (½)

c² = 6

c = √6

(ii) Use law of sines:

a / sin A = c / sin C

(√3 − 1) / sin A = √6 / (½√3)

(√3 − 1) / sin A = 2√2

½ (√3 − 1) = √2 sin A

½ (√6 − √2) = 2 sin A

¼ (√6 − √2) = sin A

Use a calculator:

A = 15°

(iii) Use SAS area:

A = ½ ab sin C

A = ½ (√3 − 1) (√3 + 1) sin 60°

A = ½ (3 − 1) (½√3)

A = ½√3