# Math Help - Finding values for expressions

1. ## 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

2. Originally Posted by damonneedshelp
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

3. 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.

4. Originally Posted by DivideBy0
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