Question

sin (30° - A) + sin (30° + A)
Hi
18.
cos (30° – A) - cos (30° + A)
= cot A. Cu​

Answer 1

Answer:

cos

(

60

∘

−

A

)

+

sin

(

30

∘

−

A

)

cos

(

30

∘

−

A

)

−

sin

(

60

∘

−

A

)

=

cot

A

Answer 2

Step-by-step explanation:

simply...we know a formula: sin(A-B)+sin(A+B)= 2 sinAcosB

and cos(A-B)-cos(A+B)= 2 sinAsinB

in first problem....A= 30, B=A

so, by putting formula..

2sin30cosA

sin30= 1/2

so, 2(1/2)cosA= cosA

so, answer: cosA

in second problem....A= 30, B=A

so, 2sin30sinA

= 2(1/2)sinA

=sinA

so, answer: sinA

hope it helps you!