Trigonometry

Question 1

1 radian – in degrees

Answer 1

180 / π degrees

Question 2

2 π radians – in degrees

Answer 2

360º

Question 3

cos (A + B)

Answer 3

cos A cos B - sin A sin B

Question 4

cos (A - B)

Answer 4

cos A cos B + sin A sin B

Question 5

cos 2A – (sin form)

Answer 5

1 - 2sin² A

Question 6

cos 2A – (cos form)

Answer 6

2cos² A - 1

Question 7

cos 2A – (both)

Answer 7

cos² A - sin² A

Question 8

cos 30º

Answer 8

sqrt(3) / 2

sqrt is an abbreviation for “square root”

Question 9

cos 45º

Answer 9

1 / sqrt(2)

sqrt is an abbreviation for “square root”

Question 10

cos 60º

Answer 10

1/2

Question 11

cos x

Answer 11

adjacent / hypotenuse

Question 12

sin (A + B)

Answer 12

sin A cos B + cos A sin B

Question 13

sin (A - B)

Answer 13

sin A cos B - cos A sin B

Question 14

sin 2A

Answer 14

2 sin A cos A

Question 15

sin 30º

Answer 15

1/2

Question 16

sin 45º

Answer 16

1 / sqrt(2)

sqrt is an abbreviation for “square root”

Question 17

sin 60º

Answer 17

sqrt(3) / 2

sqrt is an abbreviation for “square root”

Question 18

sin x

Answer 18

opposite / hypotenuse

Question 19

tan 30º

Answer 19

1 / sqrt(3)

sqrt is an abbreviation for “square root”

Question 20

tan 45º

Answer 20

1

Question 21

tan 60º

Answer 21

1 / sqrt(3)

sqrt is an abbreviation for “square root”

Question 22

tan x

Answer 22

opposite / adjacent

Question 23

xº – in radians

Answer 23

(π / 180) * x radians

* is often used to denote multiplication to avoid confusion with x

Question 24

x radians – in degrees

Answer 24

(180 / π) * x degrees

* is often used to denote multiplication to avoid confusion with x

Question 25

amplitude (trig)

Answer 25

The ampiltude of a trigonmetric function is half the distance between the minimum and maximum values.

(max - min)/2

Question 26

period (trig)

Answer 26

For a repeating function like y = sin x, or y = cos x, the period is the horizontal length of one complete wave or cycle.

Question 27

frequency (trig)

Answer 27

The number of cycles a trig function completes in a given interval, usually 360º or 2π radians for the sine or cosine functions.

Question 28

phase angle

Answer 28

In y = sin (x + d), the constant d, controls the distance the graph of y = sin x is shifted along the x-axis.

If d is positive the shift is to the left. If d is negative the shift is to the right.