Question

if you'll answer this question (D1) you are brainliest

Answer 1

Dear here is ur solution,

cosa+cosb+cosc+cos(a+b+c)

Using formula formula

2cosa+b/2cosa-b/2+cosc+cos(a+b+c)

Again using formula

=2cosa+b/2cosa-b/2+2cos(a+b+2c) /2cosa+b/2

Taking common 2cosa+b/2

Then 2cosa+b/2[2cosa-b/2+cos
a+b+2c/2]

Again using formula

2cosa+b/2[2cosb+c/2cosc+a/2]

Now 4cos(a+b) /2cos(c+a) /2cos(b+c) /2

Hope it will help you

Answer 2

Answer:

this ia the answer foe this question