If cosα+cosβ+cosγ = sinα+sinβ+sinγ = 0, show that

If cosα+cosβ+cosγ = sinα+sinβ+sinγ = 0, show that

1) cos3a+cos3ß+cos3? = 3cos(a+ß+?)
and
2) sin3a+sin3ß+sin3? = 3sin(a+ß+?)

Match the items on the right to the items on the left.

Step 1

Step 2

Step 3

Step 4

Step 5

step 1.PNG

step 2.PNG

step 3.PNG

step 4.PNG

step 5.PNG