- #1

- 54

- 2

## Homework Statement

Hi Could somebody please check my working to see if I have solved the following equations properly?

## Homework Equations

1) cos2θ = sin θ

2) sin 2θ - 1 = cos2θ

## The Attempt at a Solution

Scanned working attached

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- Thread starter Enochfoul
- Start date

- #1

- 54

- 2

Hi Could somebody please check my working to see if I have solved the following equations properly?

1) cos2θ = sin θ

2) sin 2θ - 1 = cos2θ

Scanned working attached

- #2

epenguin

Homework Helper

Gold Member

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- 895

It is easy for you to check whether the results are correct! Just see if they work.

It is pretty obvious they are the only solutions. But if there were ever any doubt in a problem like this, you need only do a graph from 0 to 360°.

- #3

ehild

Homework Helper

- 15,543

- 1,912

Check if all your results are solutions.## Homework Statement

Hi Could somebody please check my working to see if I have solved the following equations properly?

## Homework Equations

1) cos2θ = sin θ

2) sin 2θ - 1 = cos2θ

## The Attempt at a Solution

Scanned working attached

It would have been easier to substitute cos(2θ) with 2cos

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