Why function of Trigonometric are important?

Why?

Why are these functions important?

• Because they let us work out angles when we know sides
• And they let us work out sides when we know angles

Example: Use the sine function to find "d"

We know:

• The cable makes a 39° angle with the seabed
• The cable has a 30 meter length.

And we want to know "d" (the distance down).

Start with:		sin 39° = opposite/hypotenuse
		sin 39° = d/30
Swap Sides:		d/30 = sin 39°
Use a calculator to find sin 39°:		d/30 = 0.6293...
Multiply both sides by 30:		d = 0.6293… x 30
		d = 18.88 to 2 decimal places.

The depth "d" is 18.88 m