prove that cos 2x =2cos²x-1
Answers
Answered by
0
Answer:
Answer is 1
Step-by-step explanation:
Use the identity: cos (a + b) = cos a.cos b - sin a.sin b
cos
2
x
=
cos
(
x
+
x
)
=
cos
x
.
cos
x
−
sin
x
.
sin
x
=
cos
2
x
−
sin
2
x
=
=
cos
2
x
−
(
1
−
cos
2
x
)
=
2
cos
2
x
−
1
Answered by
0
Step-by-step explanation:
I hope this answers is helpful for you plz like me
Attachments:
Similar questions