Question

4
cot 53
ving:
7 sin2 34° + sin2 56° + 2 tan 18° tan 72° - cot? 30° without using trigonometrical table
​

Answer 1

Answer:Given:

sin

2

34

∘

+sin

2

56

∘

+2tan18

∘

tan72

∘

−cot

2

30

∘

=sin

2

34

∘

+sin

2

(90

∘

−34

∘

)+2tan18

∘

tan(90

∘

−18

∘

)−cot

2

30

∘

=sin

2

34

∘

+cos

2

34

∘

+2tan18

∘

cot18

∘

−(

3

​

)

2

=1+2tan18

∘

×

tan18

∘

1

​

−3

=1+2−3

=0

Step-by-step explanation: