Question

please fast plz plz !
if tan x + cot x = 3 then show that tan^2x+cot^2x = ?

Answer 1

tan x+cot x=3

squaring both side

(tan x +cot x)=9


tan^2 x +cot^2 x +2tan xcot x=9

tan^2 x +cot^2 x+2=9(tan xcotx =1)

so tan^2 x+cot^2 x =9-2=7