34 CHAP

34 CHAP - 34 HEIGHTS AND DISTANCES IMPORTANT FACTS AND...

This preview shows pages 1–2. Sign up to view the full content.

IMPORTANT FACTS AND FORMULAE 1.We already know that: In a rt.angled ∆ ΟΑΒ, where BOA = θ, i)sin θ = Perpendicular/Hypotenuse = AB/OB; ii)cos θ = Β ase/Hypotenuse = OA/OB; iii)tan θ = Perpendicular/Base = AB/OA; iv)cosec θ = 1/ sin θ = ΟΒ/ΑΒ; v)sec θ = 1/ cos θ = OB/OA; vi)cot θ = 1/ tan θ = OA/AB. 2. Trigonometrical identities: i)sin 2 θ + cos 2 θ = 1. ii)1+tan 2 θ = sec 2 θ iii)1+cot 2 θ = cosec 2 θ 3. Values of T-ratios:- θ 0 30 ° 45 ° 60 ° 90 ° Sin θ 0 ½ 1/ √2 √3/2 1 Cos θ 1 √3/2 1/ √2 ½ 0 Tan θ 0 1/ √3 1 √3 Not defined 4. Angle of Elevation: Suppose a man from a point O looks up an object P, placed above the level of his eye. Then, the angle which the line of sight makes with the horizontal through O, is called the angle of elevation of P as seen from O. Angle of elevation of P from O = AOP. 5. Angle of Depression : Suppose a man from a point O looks down at an object P, placed below the level of his eye, then the angle which the line of sight makes with the horizontal through O, is called the angle of depression of P as seen from O. hypotenuse

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 08/13/2011 for the course FSD 011 taught by Professor Vinh during the Spring '11 term at Beacon FL.

Page1 / 5

34 CHAP - 34 HEIGHTS AND DISTANCES IMPORTANT FACTS AND...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online