cos^2 2A-sin^2A=cosA.cos3A
Answers
Answered by
1
Answer:
It is proved by
sin
2
θ
+
cos
2
θ
=
1
Explanation:
Explanation:
LHS=
cos
2
(
2
A
)
−
cos
2
(
A
)
LHS=
1
−
sin
2
(
2
A
)
−
(
1
−
sin
2
A
)
LHS=
1
−
sin
2
(
2
A
)
−
1
+
sin
2
A
LHS=
sin
2
A
−
sin
2
(
2
A
)
LHS=RHS
Similar questions