how to know where to use sin A or cos A or tan A in height and distance questions?
Answers
Answer:
Step-by-step explanation:From this topic, usually, questions from heights and distances is asked. Sometimes, it has been observed that straight forward questions from trigonometric ratios such as questions based on quadrants, small simplification questions, etc. have also been asked in addition to heights and distances. Concepts of trigonometry are applicable if and only if the triangle is a right angled triangle.
π radian = 180 degrees
sin θ = Perpendicular / Hypotenuse
cos θ = Base / Hypotenuse
tan θ = Perpendicular / Base
In the first quadrant, all trigonometric ratios (sin, cos, tan, cosec, sec, cot) are positive.
In second quadrant, only sin and cosec are positive.
In third quadrant, only tan and cot are positive.
In fourth quadrant, only cos and sec are positive.
sin2θ + cos2θ = 1
1 + tan2θ = sec2θ
1 + cot2θ = cosec2θ
sin(- θ) = – sin θ
cos(- θ) = cos θ
tan(- θ) = – tan θ
cosec(- θ) = – cosec θ
sec(- θ) = sec θ
cot(- θ) = – cot θ