find the. values cos225°
Answers
Answered by
2
Hope it is Correct ✌️✌️✌️
Mark me brainlist ✌️✌️✌️
Attachments:
Answered by
1
cos 225 can be expressed as
cos 225= cos (180 +45)
We know the identity
cos(A+B)=cos(A)⋅cos(B)−sin(A)⋅sin(B)
Hence,
cos (180 + 45) = cos 180. cos 45 – sin 180.sin 45
Substituting the values of the above angles we get
cos 180= -1
cos 45=√2/2
sin 180 =0
sin 45= √2/2
cos (180 + 45) = -1 .(√2/2) – 0 . (√2/2)
= -√2/2
= – √2/2
cos 225 = – √2/2
cos 225 = – √2/2
Similar questions