Question

if sin(2x)=1/2

find the value of cos(x)-1

Answer 1

The answer will be 1/-1

Answer 2

$given \: \sin(2x) = \frac{1}{2} \\ \\ but \: we \: know \: that \: \\ \\ \sin(30) = \frac{1}{2} \\ \\ therefore \\ \\ \sin(2x) = \sin(30) \\ \\ 2x = 30 \\ \\ x = \frac{30}{2} \\ \\ x = 15 \\ \\ therefore \cos(x) - 1 \\ \\ = \cos(15) - 1 \\ \\ = - 0.759688 - 1 \\ \\ = - 1.759688 \: \: \: (approximately) \\ \\ hope \: it \: helps....$