Question

using the formula,cos A = $\sqrt{1+cos2A/2}$,find the value of cos30°,it being given that
cos60° =1/2.​

Answer 1

Step-by-step explanation:

Given Formula : cosA = √1 + cos2A / 2

Also, cos60 = 1/2

Required to find : cos30

Now,

Let A = 30 , 2A = 60°

cosA = √1 + cos2A / 2

cos30 = √( 1 + 1/2 ) / 2

cos30 = √(3/2)/2

cos30 = √(3/4) = √3 / 2

Therefore , cos30 = 

Answer 2

hi paro sis I missed u alot (;´༎ຶٹ༎ຶ`)

i am Aman ...

sister where u were these many days..

are u fine now sis ?