Ch.9 Trigonometric ratios

Question 1

what is the cosine rule to find a missing side?

Answer 1

a² = b² + c² - 2bcCosA

Question 2

what is the cosine rule fo find a missing angle?

Answer 2

CosA = ( b² + c² - a² ) ÷ 2bc

Question 3

what are the 2 scenarios when you would use the cosine rule?

Answer 3

1 - if you know two sides and the angle in between
2 - if you know all three sides

Question 4

what is the sine rule when finding a missing angle?

Answer 4

a÷SinA = b÷SinB = c÷SinC

Question 5

what is the sine rule when finding a missing angle?

Answer 5

SinA÷a = SinB÷b = SinC÷c

Question 6

how would you find the area of a triangle using trig?

Answer 6

½abSinC

Question 7

how often does y = sinθ repeat itself?

Answer 7

every 360°

Question 8

what is the y-intercept of y = sinθ?

Answer 8

0

Question 9

when does y=sinθ cross the x-axis?

Answer 9

…, -180°, 0°, 180°, 360°, …

Question 10

how often does y=cosθ repeat itself?

Answer 10

every 360°

Question 11

what is the y-intercept of y=cosθ?

Answer 11

1

Question 12

where does y=cosθ Cross the x-axis?

Answer 12

…, -90°, 90°, 270°, 450°, …

Question 13

how often does y=tanθ repeat itself?

Answer 13

every 180°

Question 14

what is the y-intercept of y=tanθ?

Answer 14

0

Question 15

where does y=tanθ have vertical asymptotes?

Answer 15

it has vertical asymptotes at …, -90°, 90°, 270°, …

Question 16

what does y = tan(x + 45) mean?

Answer 16

the graph of y = tanθ moves to the left by 45 or the x intercepts get 45 subtracted

Question 17

what does y = sin(x-90) mean?

Answer 17

the graph of y=sinθ moves to the right by 90 or the x intercepts get 90 added to them

Question 18

what does y = cosx +1 mean?

Answer 18

the graph y = cosx moves up by 1 or has its y - coordinates added to 1

Question 19

what does y = sinx - 2 mean?

Answer 19

the graph y = sinx gets moved down by 2 or has 2 subtracted from y-coordinates

Question 20

what does y = 2sinx mean?

Answer 20

the graph of y = sinx gets vertically stretched or the y-coordinates get multiplied by 2

Question 21

what does y = cos4x mean?

Answer 21

the graph of y = cosx gets horizontally squished or the x-coordinates are multiplied by ¼

Question 22

what does y = tan( -x ) mean?

Answer 22

the graph of y = tanx is reflected in the y-axis or the x-coordinates are negated

Question 23

what does y = -sinx mean?

Answer 23

the graph of y = sinx is reflected in the x-axis or the y-coordinates are negated