Trigonometry

Question 1

What is the conversion between degrees and radians?

Answer 1

1 degree = pi/180 rad

Question 2

What is the conversion between radians and degrees?

Answer 2

1 rad = 180/pi degrees

Question 3

How do you set up your calculator into radians?

Answer 3

shift –> setup –> 4

Question 4

Draw the quadrant/angle table.

Answer 4

see notes

Question 5

Draw the quadrant diagram.

Answer 5

see notes

Question 6

Draw the y = sin o graph.

Answer 6

see notes

Question 7

Draw the y = cos o graph.

Answer 7

see notes

Question 8

Draw the y = tan o graph.

Answer 8

see notes

Question 9

How can we solve for unknown angles?

Answer 9

Inverse of trigonometric functions:

y = sin (x) –> x = sin-1 (y)

Question 10

State the cosine rule.

Answer 10

a2 = b2 + c2 - 2bc cos A

Question 11

State the sine rule.

Answer 11

sin A/a = sin B/b = sin C/c

Question 12

In what cases do we use the cosine rule?

Answer 12

For working out unknown lengths of non-right angled triangles.

Question 13

What do cartesian co-ordinates refer to?

Answer 13

see diagram

Question 14

What do polar co-ordinates refer to?

Answer 14

see diagram

Question 15

How do we convert polar coordinates to cartesian?

Answer 15

x = rcos o
y = rsin o

Question 16

How do we convert cartesian coordinates to polar?

Answer 16

r = square root: x2 + y2
theta = tan-1 (y/x)