TRIGONOMETRIC RATIOS Chapter 9.5
New Vocabulary Trigonometric Ratio: The ratio of the lengths of two sides or a right triangle. The three basic trigonometric ratios are SINE, COSINE, and TANGENT. OPPOSITE?? ADJACENT??
Trigonometric Ratios Explained b a c C B A HYPOTENUSE Side ADJACENT to <A Side OPPOSITE <A
Trigonometric Ratios SINE (SOH) b a c C B A HYPOTENUSE Side ADJACENT to <A Side OPPOSITE <A Sin A = Side Opposite <A = O = a Hypotenuse H c
Trigonometric Ratios COSINE (CAH) b a c C B A HYPOTENUSE Side ADJACENT to <A Side OPPOSITE <A Cos A = Side Adjacent <A = A = b Hypotenuse H c
Trigonometric Ratios TANGENT (TOA) b a c C B A HYPOTENUSE Side ADJACENT to <A Side OPPOSITE <A Tan A = Side Opposite <A = O = a Side Adjacent <A A b
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What COLOR side is OPPOSITE <A? A
What COLOR side is ADJACENT TO <A? A
What COLOR side is the HYPOTENUSE? A
What is the sin of <X ? Y X Z
What is the tan of <Y ? Y X Z
What is the cos of <X ? Y X Z
What are the sin, cos, and tan of <H? H
Using a Calculator to Find Trigonometric Ratios for Specific Angles You can find the trigonometric ratios for specific angles using a calculator… Step 1: Make sure your calculator is in DEGREES!!! Go to MODE, and select degrees if necessary. Step 2: Select the button for the trig. function you would like to use. Step 3: Type the angle measure into the parenthesis. Step 4: Close parenthesis and press enter! Step 5: Round the answer to the desired number of decimal places.
Using a Calculator to Find Trigonometric Ratios for Specific Angles ROUND ANSWERS to four decimal places! Example 1: What is the sine of 25 degrees? Example 2: What is the tangent of 18 degrees? Example 3: What is the cosine of 49 degrees?