Question

If x+y+z=π and cosx cosy= cosz then tanx tany is equal to?​

Answer 1

Step-by-step explanation:

tan x=18/tan y.......(1)

Replace z=180-(x+Y) in the second equation and we ge

tan y.tan (180 - (x+y))=2

tan y.tan (x+y) = -2

tan y. (tan x + tan y)/1-tan x.tan y = -2

(tan y.tan x + tan^2 y)/(1-tan x.tan y) = -2

Let tan y = p

18 + p^2=-2(1-18)

p^2=34-18

p=+-4

Thus tan y = 4 assuming x,y,z are angles of a triangle