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Old March 27th, 2007, 12:34 PM
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Default Finding values for expressions

Im asked to find these two values without using a table or calculator.

1) Sin1.2(degrees)

2) Tan 0.7(degrees)

thank you for any help
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Old March 31st, 2007, 12:52 PM
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Originally Posted by damonneedshelp View Post
Im asked to find these two values without using a table or calculator.

1) Sin1.2(degrees)

2) Tan 0.7(degrees)

thank you for any help
Hello,

if you have very small angles in radians you can use the property:

sin(x) ≈ tan(x) ≈ x

to 1): That means: Calculate the radians of 1.2° :

x = 1.2/360 * pi = pi/150 ≈ 0.021 (you can guess this value using pi ≈ 3.14) Therefore you get:

sin(1.2°) ≈ 0.021

to 2): Calculate the radians of 0.7°:

x = 0.7/3600 * pi (use pi ≈ 22/7) ≈ 22/3600 = 11/1800 ≈ 1/180 ≈ 0.006
Therefore you get:

tan(0.7°) ≈ 0.006

Please check my calculations with a calculator

EB
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Old March 31st, 2007, 10:27 PM
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I got

sin(1.2) = 0.020942419883...
tan(0.7) = 0.12217912662...

So the sin approximation seems about right, but the tan approximation is quite a bit off.
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Old April 2nd, 2007, 01:46 PM
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Originally Posted by DivideBy0 View Post
I got

sin(1.2) = 0.020942419883...
tan(0.7) = 0.12217912662...

So the sin approximation seems about right, but the tan approximation is quite a bit off.
Hello,

you calculated tan(7.0)

EB
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