calculator

7 Trigonometric ratios on the calculator

There are several different types of units that an angle can be measured, with degrees being one of the possibilities. Before you use the calculator to find the trigonometric angles in degrees, you should ensure that it is set to utilize the appropriate units.

Always ensure that the calculator is using the correct system of angle measurement before using trigonometric ratios.

This calculator is programmed to use degrees when the indicator on the display is visible at the top of the screen. If you see the indicator in the upper right hand corner the indicator, then you're calculator is set to use different units when measuring angles.Figure 9 The setting of degrees

To adjust the calculator so that it works in degrees, you must use the key sequence (SETUP) (Deg).

To calculate the sine, cosine or tangent of an angle, press the , or key and then enter the size of the angle. Note that the , and keys automatically open the bracket for you to open a bracket for. If you're only calculating the sine, cosine , or tangent of an angle, just enter the numbers after when you've entered your angle and there is not a need for closing the bracket. If you're using the ratios as part of an overall calculation that you want to calculate, you'll have to ensure that you close the bracket on your own (by press ) before you enter the remainder of the calculation.

The older versions of calculator have the required angle to be input first, which is then followed by , or button.

Activities 16: Trigonometric Ratios using your calculator

Determine the worth of each of these using your calculator Answer the questions right to 3 significant numbers.

The answer is revealed

It is evident from the explanation to section (3) you will notice that this calculator presents the ratios of some angles as fractions, which may include surds, and not in decimal form.

The decimal form can be found using or .Previous6.2 Inserting a missing rootNext8 Finding angles from trigonometric ratiosMU123_1PrintPrint

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