mohon bantuan nya dgn cara :) trimakasih

6. sin 45 = x/8
√2 / 2 = x / 8
2x = 8√2
x = 4√2
sin 30 = 4√2 / k
1 / 2 = 4√2 / k
k = 4√2 × 2 = 8√2

7. 2cos x + 1 = 0
2cos x = -1
cos x = -1/2
x = -240, -120, 120, 240

8. 2 sin x - 1 = 0
2 sin x = 1
sin x = 1/2
x = 30, 150