Question

if tita is
30°
prove that cos 2 tita = cossquare tita -. sin square tita​

Answer 1

Step-by-step explanation:

Given,

∅ = 30°

cos²∅ = cos²∅ - sin²∅

Now,

cos²30° = cos²30° - sin²30°

(√3/2)² = (√3/2)² - (1/2)²

¾ = ¾ - ¼

¾ = 3-1/4

¾ = 2/4

¾ = ½

= ½ - ¾

= 4 - 6/8

= -2/8

= -¼.