Question

2sin(105)cos(105)

Answer 1

\[\sin 2x = 2sinx \ cosx\]

Answer 2

so...
\[2 \sin 105 \ \cos 105 = \sin (105 \times 2) = \sin (210)\]

Answer 3

the 105 are degrees

Answer 4

\[\sin (210) = \sin ( 180 + 30) = \sin ( 2\pi + \frac{ \pi }{ 6 } ) = \sin \frac{ \pi }{ 6 } = \sin 30 \]

Answer 5

which means
\[\sin 30 = \frac{ 1 }{ 2 }\]

got it :) ?

Answer 6

yes! thank you so much!

Answer 7

u r welcome!

Answer 8

210 is in the 3rd quadrant. what is the sign of the sine function?