Question

sin 2A=sinA is true then A =​

Answer 1

Answer:

A = 0

Step-by-step explanation:

hi friend.,

given sin2A=2sinA

we know that sin2A=2sinAcosA

so, 2sinAcosA=2sinA

divide with 2sinA on both sides ,we get

cosA=1

cosA=cos0

A=0

Answer 2

The value of A = 60°

Given:

Sin 2A = Sin A  

To find:

The value of A

Solution:  

Condition used:

From trigonometric identities

Sin 2A = 2 Sin A Cos A  

Given that

Sin 2A = Sin A  

By the given condition Sin 2A = 2 Sin A Cos A  

=>  2 Sin A Cos A = Sin A

Divide by Sin A into both sides

=> [ 2 Sin A Cos A]/Sin A = Sin A/Sin A

=> 2 Cos A = 1

=> Cos A = ½

As we know Cos (60°) = ½

=> Cos A = Cos 60°

=> A = 60  

Therefore,

The value of A = 60°

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