Given sin x = -4/5 and x is in quadrant 3, what is the value of tan x/2

bearing in mind that, on the III Quadrant, sine as well as cosine are both negative, and that hypotenuse is never negative, so, if the sine is -4/5, the negative number must be the numerator, so sin(x) = (-4)/5.

Step-by-step explanation:

Look at the pictures.

We have

Calculate the value of x:

In Quadrat III, cosine is negative. Therefore x = -3.

Calculate the cosine:

Substitute to the formula of the tan x/2:

b.-4 units

all you   do is count how many times you move

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.