Download File - Regular Physics

Trigonometry Notes
Sine
(sin)
Sin(X) = Opposite
Hypotenuse
Example: Solve for x
Cosine
(cos)
Cos(X) = Adjacent
Hypotenuse
Example: Solve for x
cos(45) = 10
x
Sin(30) = x =
8
Tangent
(tan)
Tan(X) = Opposite
Adjacent
Example: Solve for x
Tan(55) = 200
x
Easy way to SOHCAHTOA:
remember
SOH=sin=opp CAH=cos=adj TOA=tan=opp
all this
hyp
hyp
adj
Things to
remember:
1.) All angles in a RIGHT
triangle will add up to 180o
?
52o
2.) A straight line equals 180o
48o
?
3.) Pythagorean Theorem
H2 = A2 + O2
6
?
8
Inverse
Trig
Functions
What if we don’t know the angles?
Then continue using SOHCAHTOA:
1.)We know the opp. & hyp. but not the angle:
sin-1 (opp/hyp) = angle
2.) We know the adj. & hyp. but not the angle:
cos-1 (adj/hyp) = angle
3.) We know the opp. & adj. but not the angle:
tan-1 (opp/adj) = angle
WE ARE JUST WORKING BACKWARDS!!
How to
use your
calculator
1.) Make sure your calculator is in DEGREE
MODE!
Go to Mode and select Degrees and not Radians
2.) Use the inverse trig buttons.
3.) Example problem: What angle did Superman
take off from the building?
cos-1 (75/100) =
41.41o