Trigonometry (1)

Question 1

Convert degrees to radians

Answer 1

Divide by 180, multiply by pi

Question 2

Divide by 180, multiply by pi

Answer 2

Convert degrees to radians

Question 3

Convert radians to degrees

Answer 3

Divide by pi, multiply by 180

Question 4

Divide by pi, multiply by 180

Answer 4

Convert radians to degrees

Question 5

Pythagoras theorem

Answer 5

a^2 + b^2 = c^2

Question 6

a^2 + b^2 = c^2

Answer 6

Pythagoras theorem

Question 7

Get trig values from triangle

Answer 7

Put in sin(30), should equal 1/2

Question 8

Put in sin(30), should equal 1/2

Answer 8

Get trig values from triangle

Question 9

What is a unit circle?

Answer 9

A circle with radius 1, at origin 0

Question 10

A circle with radius 1, at origin 0

Answer 10

What is a unit circle?

Question 11

Find arc length of sector

Answer 11

Length = radius * pheta

Question 12

Length = radius * pheta

Answer 12

Find arc length of sector

Question 13

Find the area of a sector

Answer 13

Area = 1/2 * r^2 * pheta

Question 14

Area = 1/2 * r^2 * pheta

Answer 14

Find the area of a sector

Question 15

The sine rule

Answer 15

a/sinA = b/sinB = c/sinC

Question 16

a/sinA = b/sinB = c/sinC

Answer 16

The sine rule

Question 17

The cosine rule

Answer 17

a^2 = b^2 + c^2 - 2bc * cosA

Question 18

a^2 = b^2 + c^2 - 2bc * cosA

Answer 18

The cosine rule

Question 19

The cosine rule for an angle

Answer 19

cosA = (b^2 + c^2 - a^2)/2bc

Question 20

cosA = (b^2 + c^2 - a^2)/2bc

Answer 20

The cosine rule for an angle

Question 21

Solve 2 sin x + 5 cos x = R sin (x + a)

Answer 21

2 sin x + 5 cos x = R sin x cos a + R cos x sin a

R cos a = 2 and R sin a = 5

tan^-1 (5/2)

¬(2^2 + 5^2) = ¬29

¬29 sin (x + 68.2degrees)