Trig Flashcards
Cosine Law
a^2=b^2+c^2-2bcCosA
Sine Law
SinA/a = SinB/b = SinC/c = …
Sin0
0
Sin30
Root1 /2
Sin45
Root2 /2
Sin60
Root3 /2
Sin90
Root4 /2 aka 1
Cos0
Root4 /2 aka 1
Cos30
Root3 /2
Cos45
Root2 /2
Cos60
Root1 /2
Cos90
0
Tan0
0
Tan30
1/root3
Tan45
1
Tan60
Root3
Tan90
Undefined
Reciprocal identity (sin)
Sinx = 1/cscx
Reciprocal Identity (cos)
Cosx = 1/secx
Reciprocal identity (tan)
Tanx = 1/cotx
Reciprocal identity (csc)
Cscx = 1/sinx
Reciprocal identity (sec)
Secx = 1/cosx
Reciprocal identity (cot)
Cotx = 1/tanx
Quotient identity
Tanx = sinx/cosx
Cotx = cosx/sinx
Pythagorean identity
sin^2x + cos^2x = 1
1 + cot^2x = csc^2x
Tan^2x + 1 = sec^2x
Angle less than 90
Measure the sides
a >/= b, one solution
a < b, bSinA
a = bSinA
One solution
a < bSinA
No solutions
a > bSinA
Two solutions
Angle greater than/equal to 90
Measure the sides
a>b, one solution
a = b, no solutions