Question

cos-105
A) (squareroot6)+(squareroot2)/4
B)(squareroot6)-(squareroot2)/4
C)(squareroot2)-(squareroot6)/4
D)-(squareroot6)-(squareroot2)/4

Answer 1

@ganeshie8

Answer 2

hint : \(\cos (-\theta) = \cos (\theta)\)

Answer 3

hint2 : \(105 = 60 + 45\)

Answer 4

I use cosAcosB-sinAsinB or CosAcosB-sinAsinB

Answer 5

^^^^^^^^^^^^+

Answer 6

\(\cos (A +B) = \cos A \cos B \color{red}{-} \sin A \sin B\)

Answer 7

\(\cos (-105) = \cos (105) = \cos(60+45) ~= ~?\)

Answer 8

cos60cos45-sin60sin45

Answer 9

Yep ! look up ur unit circle

Answer 10

\[1/2*\sqrt{2}/2-\sqrt{3}/2*\sqrt{2}/2\]

Answer 11

Perfect ! simplify...

Answer 12

\[\sqrt{2}/4-\sqrt{6}/4\]

Answer 13

so my answer is c

Answer 14

\(\large \color{Red}{\checkmark }\)

Answer 15

good job !!