सरल कीजिए: \sin (30^\circ-{A})+\sin (30^\circ+{A})

RRB JE Stage I 1 Jun 2019 Shift 1 (HM)

Question : 23 of 100

Marks: +1, -0

सरल कीजिए:

\sin (30°-{A})+\sin (30°+{A})

Solution:

\∵ \sin {C}+\sin {D}

=2 \sin {C+D}/{2} \.\cos {C-D}/{2}

\∴\sin (30°+{A})+\sin (30°-{A})

=2 \sin {30°+A+30°-A}/{2} \.

\cos {30°+A-30°+A}/{2}

=2 \sin 30°.\cos A=2 \×{1}/{2} \cos A

=\cos A

Go to Question:

Prev Question

Next Question