PRO Trig Flashcards
What function can be placed over one to get csc?
Sin
What function can be placed over one to get sec?
Cos
What function can be placed over one to get cot?
What functions can be placed over each other to get cot?
Tan, Cos/Sin
What function can be placed over one to get sin?
Csc
What function can be placed over one to get cos?
Sec
What function can be placed over one to get tan?
What functions can be placed over each other to get tan?
Cot, Sin/Cos
What is the first “Pythagorean” identity?
Sin^2 + Cos^2 = 1
How do you get the second and third “Pythagorean” identities?
Divide by Sin^2 and Cos^2
What are sin, cos, and tan in terms of x and y? (On the unit circle)
Sin=Y, Cos=x, and Tan=y/x
What is sin(-t)?
-Sin(t)
What is cos(-t)?
Cos(t)
What is tan(-t)?
-Tan(t)
What is sin(a+b)?
Sin(a)Cos(b) + Cos(a)Sin(b)
What is sin(a-b)?
Sin(a)Cos(b) - Cos(a)Sin(b)
What is cos(a+b)?
Cos(a)Cos(b) - Sin(a)*Sin(b)
What is cos(a-b)?
Cos(a)Cos(b) + Sin(a)*Sin(b)
What is tan(a+b)?
(Tan(a)+Tan(b))/(1-Tan(a)*Tan(b))
What is tan(a-b)?
(Tan(a)-Tan(b))/(1+Tan(a)*Tan(b))
What is Sin(2a)?
2Sin(a)Cos(a)
What is Cos(2a)?
Cos^2(a)-Sin^2(a), which you can use the first P identity to get 1-2Sin^2(a) or 2Cos(a)^2-1
What is Tan(2a)?
(2*Tan(a))/(1-Tan(a)^2)
What is Sin(a/2)?
+/- The square root of (1-Cos(a))/2
What is Cos(a/2)?
+/- The square root of (1+Cos(a))/2
What is Tan(a/2)?
+/- The square root of (1-Cos(a))/(1+Cos(a)) which is equal to (1-Cos(a))/Sin(a) or Sin(a)/(1+Cos(a))
What is Sin(x) + Sin(y)? (Might not need to know)
2Sin(x+y over 2)Cos(x-y over 2)