Question

Oбчисліть cos150 tg120

Answer 1

cos150=cos(180°-30°)=cos180°cos30°+sin180°sin30° =-cos30°= -(√3)/2

tg120=tg(180-60)=-tg60= -√3

Answer 2

To calculate the values of cos(150°) and tg(120°), you can use the trigonometric identities and unit circle:

1. cos(150°): cos(150°) = cos(180° - 30°)

Now, we know that cos(180°) = -1 and cos(30°) = √3/2.

So, cos(150°) = -cos(30°) = -√3/2.

2. tg(120°): tg(120°) = tan(120°)

Now, we know that tan(120°) can be expressed in terms of sin(120°) and cos(120°).

sin(120°) = √3/2 (you can find this by considering the unit circle)

cos(120°) = cos(180° - 60°) = -cos(60°) = -1/2

Now, tg(120°) = sin(120°) / cos(120°) = (√3/2) / (-1/2) = -√3.

So, the values are:

cos(150°) = -√3/2 tg(120°) = -√3