Did I do this problem right?

[watchthesky30]

Hi. I want to see if I did this question correctly. You don't have to give me the answer, just tell me if it is right or wrong. Thank you!

Evaluate the expression without using a calculator:
(sin(?/3)cos(?/4)-sin(?/4)cos(?/3))²

This is what I did:
[sin(?/3)cos(?/4) - sin(?/4)cos?/3)]² =

[?3/2•1/?2 – 1/?2•1/2]² =

[ (?3 – 1)/2?2 ]² = Note that (2?2 )² = 2²•2 = 8.

(?3 – 1)² / 8

 

[galactus]

Lookin' good

 

[Aladdin]

Hi. I want to see if I did this question correctly. You don't have to give me the answer, just tell me if it is right or wrong. Thank you!

Evaluate the expression without using a calculator:
(sin(?/3)cos(?/4)-sin(?/4)cos(?/3))²

This is what I did:
[sin(?/3)cos(?/4) - sin(?/4)cos?/3)]² =

[?3/2•1/?2 – 1/?2•1/2]² =

[ (?3 – 1)/2?2 ]² = take cos(pi/4)= sin(pi/4) = ?2/2 that's easier :wink: Note that (2?2 )² = 2²•2 = 8.

(?3 – 1)² / 8