Y1CH10 Trigonometric identities and equations

Question 1

How do you remember the quadrants

Answer 1

CAST diagram

Bottom right and anticlockwise

Question 2

what = 1 via sin and cos

Answer 2

Sin^2 + cos^2 = 1

Question 3

tan = in terms of sin and cos

Answer 3

sin/cos

Question 4

Double angle formula
sin2a
cos2a
tan2a

Answer 4

sin2a = 2sinacosa

cos2a = cos^2-sin^2

tan2a = 2tana/ 1- tan^2