Chapter 9 Some Applications of Trigonometry

Notes

Applications of Trigonometry:

Used to find height and distance

Based on right triangle

Important terms:

Angle of elevation

Angle of depression

Angle of elevation:

Object above eye level

Angle of depression:

Object below eye level

Important trigonometric ratios:

tanθ=

B

P

​

sinθ=

H

P

​

cosθ=

H

B

​

Standard values:

tan 30° = 1/√3

tan 45° = 1

tan 60° = √3

Important points:

Draw proper diagram

Identify opposite and adjacent side

Use correct ratio

Common mistakes:

Wrong ratio selection

Forgetting units

Confusing elevation and depression