Can someone help me??? Which of the following is equal to 1/2 or -1/2? Check all that apply.

Sin (7π/6)

Sin (4π/3)

Cos (5π/3)

Cos (π/6)

Cos (5π/6)

Sin (5π/6)

Cos (5π/3)

Cos (π/6)I think this one

Below in bold.

Step-by-step explanation:

The sine is positive in the first and second quadrants and negative in other 2.

The cosine is positive in the first and 4th quadrants and negative in other 2.

Note that sin(pi/6) = 1/2 and cos(pi/3 = 1/2).

sin(7pi/6) = 1/2  

cos(5pi/3) = 1/2

sin(5pi/6) = 1/2

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.