Question

Which one is cos(pi/6-x) equal to?

Answer 1

cos (pi/6 - x)= cos pi/6 cos x+ sin pi/6 sin x= sqrt(3)/2 cos x+ 1/2 sin x

Answer 2

So C ?

Answer 3

B it will be.. but are you clear about what i did?

Answer 4

cos (a-b)= cos a cos b + sin a sin b

Answer 5

No do you mind explaining more

Answer 6

you know formula of trigonometric ratios of compound angles?

Answer 7

The given problem has the form cos (a - b), and this form expands to

cos a * cos b + sin a * sin b. This is where

Arnab09 obtained his/her

cos (pi/6 - x)= cos pi/6 cos x+ sin pi/6 sin x= sqrt(3)/2 cos x+ 1/2 sin x

Hint: What is cos pi/6? What is sin pi/6?

Answer 8

No I dont ?

Answer 9

refer to this please: http://www.mathsrevision.net/advanced-level-maths-revision/pure-maths/trigonometry/compound-angle-formulae

Answer 10

if you understand these clearly, you will face no problem in this type of problems :)

Answer 11

Okay then thank you for your times :) and the link too!

Answer 12

no problem :)