Question

The value of coseo 10° + coseo 50° - coseo 70° is​

Answer 1

Answer:

cosec10

∘

+cosec50

∘

−cosec70

∘

=

sin10

∘

1

+

sin50

∘

1

−

sin70

∘

1

=

2sin10

∘

sin50

∘

sin70

∘

2sin50

∘

sin70

∘

+2sin10

∘

sin70

∘

−2sin10

∘

sin50

∘

=

2sin10

∘

sin(60

∘

−10

∘

)sin(60

∘

+10

∘

)

2sin70

∘

(sin50

∘

+sin10

∘

)−2sin10

∘

sin50

∘

=

2sin10

∘

sin(60

∘

−10

∘

)sin(60

∘

+10

∘

)

2sin70

∘

(2sin30

∘

cos20

∘

)−cos40

∘

+cos60

∘

=

2sin10

∘

(sin

2

60

∘

−sin

2

10

∘

)

2sin

2

70

∘

−cos40

∘

+

2

1

=

2(

4

3sin10

∘

−4sin

3

10

∘

)

1−cos140

∘

−cos40

∘

+

2

1

=

2

sin30

∘

cos40

∘

−cos40

∘

+

2

3

=

4

1

2

3

=6