Help me on this qeustion please.

- Solve for the length of the indicated side. Using knowledge that COS(150) = - (sqrt(3)/2) calculate the value of ‘x’ leaving your answer as an exact value.

StarStrike Feb 14, 2019

#1**+1 **

We know two sides and an included angle....and we are looking for the opposite side

The Law of Cosines is what we need....so

x^2 = 8^2 + 12^2 - 2(8)(12)cos 150 simplify

x^2 = 64 + 144 - (192) (-sqrt (3) / 2)

x^2 = 64 + 144 + (192) (sqrt (3) / 2) take the square root of both sides

x = √ [ 64 + 144 + (192) (sqrt (3) / 2) ]

x ≈ 19.35

CPhill Feb 14, 2019

#2**+1 **

Oh so you replace the Cos 150 with sqrt(3)/2...

I thought you had to solve that lol.

I need to read the qeustion slower.

StarStrike
Feb 14, 2019