Question

01. Cos8+ cos (240° + 0) + cos (240° - 0) =
1
3
(A)
(B) 1
(C)
c
(D)
4
4​

Answer 1

Answer:

0.50606257726

Answer 2

Answer:

Correct option is

C

4

1

f(x)=cosxcos(240−x)cos(240+x)

=cosx

2

1

[cos(480)+cos2x]

=

2

1

cosx[2cos

2

−1−

2

1

]

=

4

[4cos

2

−3]

cosx

f(x)=

4

cos3x

∴ range of f(x)ϵ[−

4

1

,

4

1

]=[−p,p]

⇒p=

4

1