1. ## Trig Question

Don't know what I am meant to do and how to work it out.

Thanks

I have attached the problem.

Don't know what I am meant to do and how to work it out.

Thanks

I have attached the problem.

note that the magnitude of the vertical side is $\sin \theta$ and the magnitude of the base is $\cos \theta$ by SOHCAHTOA.

Now apply Pythagoras' theorem

3. Thanks.

But I don't know what the question is asking me to do.

Thanks.

But I don't know what the question is asking me to do.
it is asking you to prove that $\sin^2 \theta + \cos^2 \theta = 1$

just do what i said, you will get there

5. Sorry I'm a bit thicker than most.

I don't actually understand what He means by this part of the question.

I can understand what the first part is that sin(x)^2 + cos(x)^2 = 1

But what is He trying to tell me to do.

Sorry I'm a bit thicker than most.

I don't actually understand what He means by this part of the question.

I can understand what the first part is that sin(x)^2 + cos(x)^2 = 1

But what is He trying to tell me to do.

The triangle you have been given can only be constructed if the angle $\theta$ is between 0 and 90 degrees.

Call the length of the horizontal "leg" of the triangle a. Call the length of the vertical "leg" of the triangle b. In terms of the angle $\theta$, what are the values for a and b?

Once you have that, notice that you have a right triangle. Apply the Pythagorean Theorem.

-Dan

Sorry I'm a bit thicker than most.

I don't actually understand what He means by this part of the question.

I can understand what the first part is that sin(x)^2 + cos(x)^2 = 1

But what is He trying to tell me to do.

He means for any angle theta between 0 degree and 90 degrees.
0 and 90 degrees are not included because with theta as zero degree or 90 degrees, you have no right triangle. There is already one 90-degree angle in the shown right triangle. The 3 interior angles are supposed to add up only to 180 degrees.

To picture the 0deg < theta < 90deg more, first make the theta in the figure approximately or about 5 degrees only, or 10 degrees, or dependending on how small it can get in your sketch.
The resulting triangle looks very flat, yet, still it is a right triangle and
sin^2(5deg) +cos^2(5deg) = 1 still.

Then make theta about 80 degrees. The resulting right triangle looks like a a tall pole. Yet, still, sin^2(80deg) +cos^2(80deg) = 1.

Get your calculator and check those.

8. Thanks to all of you. I worked it out finally. I wish I had \$1.00 for every hour I spent on it.

Thanks a lot.