# Inv. Trig Function

• Jan 26th 2009, 01:00 AM
Inv. Trig Function
If you want to find a value for X from which

$\displaystyle sin^-1(x) = 0.8$

I have graphed this, and is $\displaystyle X = .916$

• Jan 26th 2009, 02:01 AM
mr fantastic
Quote:

Originally Posted by ADY
If you want to find a value for X from which

$\displaystyle sin^-1(x) = 0.8$

I have graphed this, and is $\displaystyle X = .916$

Your post makes no sense.

If you want to solve $\displaystyle \sin^{-1}x = 0.8 \Rightarrow x = \sin 0.8$ then use a calculator. I get x = 0.717 (correct to 3 decimal places) assuming you're measuring angle in radians.

Otherwise, please post the question exctaly as it appears in your book or wherever it is you got it from.
• Jan 26th 2009, 02:49 AM
Apologises Mr F.

I was just clearly mashing the keypad lol.

Ok, so lets try again.

Explain how i can use the inv. trig functions on my calc to find a value of X. From $\displaystyle sin(X) = 0.8$

Thanks
• Jan 26th 2009, 02:54 AM
mr fantastic
Quote:

Originally Posted by ADY
Apologises Mr F.

I was just clearly mashing the keypad lol.

Ok, so lets try again.

Explain how i can use the inv. trig functions on my calc to find a value of X. From $\displaystyle sin(X) = 0.8$

Thanks

$\displaystyle \sin x = 0.8 \Rightarrow x = \sin^{-1} (0.8) = 0.927$ radians.