1. ## Solve trig. equations

Hi:
Solve 6cos²θ-8sinx-3=0 , in the range 0 to 2∏

I can't use Latex yet so I have uploaded a scanned attempt.
My solutions are at:
x=0.31
x=2.83

Am I close or in another game altogether?

2. Originally Posted by stealthmaths
Hi:
Solve 6cos²θ-8sinx-3=0 , in the range 0 to 2∏

I can't use Latex yet so I have uploaded a scanned attempt.
My solutions are at:
x=0.31
x=2.83

Am I close or in another game altogether?
Looks fine to me

3. Originally Posted by stealthmaths
Hi:
Solve 6cos²θ-8sinx-3=0 , in the range 0 to 2∏

I can't use Latex yet so I have uploaded a scanned attempt.
My solutions are at:
x=0.31
x=2.83

Am I close or in another game altogether?
Hi stealthmaths,

You've solved for $\displaystyle Sinx$ or $\displaystyle Sin\theta$

$\displaystyle x=\theta=Sin^{-1}(0.31),\ \pi-Sin^{-1}(0.31)$

4. Originally Posted by Archie Meade
Hi stealthmaths,

You've solved for $\displaystyle Sinx$ or $\displaystyle Sin\theta$

$\displaystyle x=\theta=Sin^{-1}(0.31),\ \pi-Sin^{-1}(0.31)$
Ignore me, I'm a spoon >.<

5. sinx=-4+√34/6
sinx=0.3
x=0.31

So I plot on the sin graph where 0.31 is and draw along to find the second point and I get ∏-0.31
giving 0.31 and 2.83

What am I missing?
I'm being a spoon?

6. Looks fine,
just checking that you took the inverse sine,
you most likely did,
answers are coincidental to 1 decimal place.

7. yes. Great!
Thank you both.
I doubt your a spoon e^(i*pi)