Math 1316
Finding Trigonometric Function Values Using a Calculator
Section 2.3 Class Notes
Example 1:
Use a calculator to find a decimal approximation for each value. Round the answers to the nearest
hundredth.
1. sin 380 42’
2. cot (-5120 20’)
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Math 1316
3.
1
sec 14.80
4.
cos 770
sin 770
Section 2.3 Class Notes
5. sin 350 cos 550 + cos 350 sin 550
6. cot 410 24’
7. cos 421030’
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8.
Section 2.3 Class Notes
1
sec 14.80
9. cos(900  3.690 )
10.
1
tan(900  220 )
11. sin 350 cos 550 + cos 350 sin 550
12. cos750 29’cos14031’ – sin 75029’sin14031’
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Math 1316
Section 2.3 Class Notes
Example 2: Use a calculator to decide whether each statement is true or false.
1. cos 400 = 2cos200
2. sin 39948’ + cos 39948’ = 1
3. cos700 = 2cos2350 – 1
4. cos(300 + 200) = cos300 + cos200
Example 3: Use a calculator, find all values of θ, if θ is in the interval [0, 3600) and has the given
function value. Leave the answer in decimal degree and round to the nearest hundredth.
1. tan = 1.4739716
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Math 1316
Section 2.3 Class Notes
2. sin θ = 0.27843196
3. sec θ = 2.7496222
4. cos θ = 1.599596
5. tan θ = 6.4358841
6. csc θ=0.70058013
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