surds and exact values

Question 1

what is a surd?

Answer 1

square root

Question 2

rationalising surds

Answer 2

get rid of square root by multiplying by square root

Question 3

rationalise 2 terms

Answer 3

use conjugate
e.g x+3 becomes x-3

Question 4

unit circle

Answer 4

30° increments 45° increments 90°increments

Question 5

radian unit circle

Answer 5

pie/6 increments pie/4 increments pie/2 increments

Question 6

degrees°—> radians

Answer 6

multiply degree° by pie/180

Question 7

radians —> degrees°

Answer 7

multiply radian by 180/pie

Question 8

circle

Answer 8

sin, all, tan, cos
(students, always, take, calc)

Question 9

sin

Answer 9

square root of bottom fingers
——————————————
2

Question 10

cos

Answer 10

square root of top fingers
————————————-
2

Question 11

tan

Answer 11

FLIP
square root of bottom fingers
——————————————-
square root of top fingers

Question 12

30° in radians

Answer 12

pie/6

Question 13

45° in radians

Answer 13

pie/4

Question 14

60° in radians

Answer 14

pie/3

Question 15

90° in radians

Answer 15

pie/2

Question 16

5 steps of finding exact values

e.g: what is the value of sin(210°)

Answer 16

1. work out which quadrant angle is in
2. us this to decide if sin cos or tan is negative or positive
3. find reference angle
4. find sin cos or tab for reference angle (exact values)
5. sin(210°) = -sin(30°)
   = -1/2