Question

Prove that:
(sin5A - 2 sin3A + sinA) / (cos5A - cosA) = tanA

Answer 1

Answer:

Solution :

1)=sin5A-sin3Acos5A+cos3A

=2sin(5A-3A2)cos(5A+3A2)2cos(5A+3A2)cos(5A-3A2)

=sinAcosA

=tanA

RHS

2)=sinA+sin3AcosA+cos3A

=(2cos((A-3A)/2)sin((A+3A)/2))/(2cos((A+3A)/2)cos((A-3A)/2)

=(2cos(-A)sin2A)/(2cos2Acos(-A)

=(sin2A)/(cos2A)

=tan2A

RHS

Answer 2

Step-by-step explanation:

first use SinC+SinD and CosC+cosD formula

then solve and at last use Cos2A and Sin2A formula.