Respuesta :

clara856

Step-by-step explanation:

first of all

[tex]tan = \ \frac{ \sin}{ \cos } [/tex]

put above of equation

(sin/cos)(sin)+cos =sec

sin²/cos +cos=sec

take l.c.m

sin²+cos²/cos=sec

as sin ²+cos²=1 so

1/cos=sec

sec=sec

hence proved