Math, asked by VISHALKUMARV22, 3 months ago

cos²60° + cos²30° + tan76° x tan14° - 2 = ?​

Answers

Answered by anjali123467
1

Step-by-step explanation:

Let cos

2

76

+cos

2

16

−cos76

cos16

=I

I=cos

2

(60

+16

)+cos

2

16

−cos(60

+16

)cos16

Using cos(A+B)=cosAcosB−sinAsinB

I=(cos60

cos16

−sin60

sin16

)

2

+cos

2

16

−(cos60

cos16

−sin60

sin16

)cos16

=

4

cos

2

16

+

4

3sin

2

16

2

3

cos16

sin16

+cos

2

16

2

cos

2

16

+

2

3

cos16

sin16

=

4

3cos

2

16

+

4

3sin

2

16

=

4

3

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