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