Question

If cos theta=0.8 and 0 10 years ago

Answer 1

hint:

\[\Large \sin(2\theta) = 2*\sin(\theta)*\cos(\theta)\]

Answer 2

you'll first need to find the value of sin(theta) before you can use that identity

Answer 3

Hint:

\(\Large cos ~\theta = \frac{adjacent}{opposite}= 0.8 = \frac{4}{5}\)