trig

Question 1

How do we work out angle x of an isosceles triangle?

Answer 1

-Split the isosceles triangle into two right-angled triangles

-Choose a right angled triangle and work out the value of half of x using trigonometry

-Work out the value of x (by doubling).

Question 2

how do we find angle x given two side lengths?

Answer 2

you need to do inverse sin,cos, or tan mutiplied by the fraction from SOHCAHTOA e.g. tan⁻¹x(24/19)

Question 3

Which type of triangle does trigonometry work for?

Answer 3

Only right angled triangles!

Question 4

If asked to work out a side length of a right angled triangle (using trig) what must we do?

Answer 4

Write and equation using sin, cos, or tan e.g. tan(62)= p/13.15
or cos(56) = 23.4/v

Question 5

When working out side lengths, how many decimal places should we go up to?

Answer 5

At least 3.

Question 6

Exact value of sinθ at 0°

Answer 6

0

Question 7

Exact value of sinθ at 30°

Answer 7

1/2

Question 8

Exact value of sinθ at 45°

Answer 8

√2/2

Question 9

Exact value of sinθ at 60°

Answer 9

√3/2

Question 10

Exact value of sinθ at 90°

Answer 10

1

Question 11

Exact value of cosθ at 0°

Answer 11

1

Question 12

Exact value of cosθ at 30°

Answer 12

√3/2

Question 13

Exact value of cosθ at 45°

Answer 13

√2/2

Question 14

Exact value of cosθ at 60°

Answer 14

1/2

Question 15

Exact value of cosθ at 90°

Answer 15

0

Question 16

Exact value of tanθ at 0°

Answer 16

0

Question 17

Exact value of tanθ at 30°

Answer 17

√3/3

Question 18

Exact value of tanθ at 45°

Answer 18

1

Question 19

Exact value of tanθ at 60°

Answer 19

√3

Question 20

Exact value of tanθ at 90°

Answer 20

∞