Question

If cosx+cosy=4/5 and cosx-cosy=2/7 show that 14 tan(x+y/2)+5 cot(x+y/2)=0

PLZ ANSWER THIS QSN I WILL MARK AS BRAINLIEST FOR THE CORRECT ANSWER...​

Answer 1

Answer:

use these formulas

CosC + CosD = 2Cos[(C+D)/2]Cos[(C-D)/2]

CosC - CosD = 2Sin[(C+D)/2]Sin[(D-C)/2]

tan[(C+D)/2]tan[(C-D)/2]= 5 / 14

so14*tan[(C-D)/2]= 5* cot[(C+D)/2]

Step-by-step explanation:

i guess this would help u