AREA OF A TRIANGLE
If D represents the area of a triangle then
D = 1/2 ab sin C = 1/2 bc sin A = 1/2 ca sin B
D = {s(s-a)(s-b)(s-c)}1/2
D = abc/4R
D = rs
where 2s= a+b+c and r is the inradius of the triangle
NOTE:
RELATION BETWEEN r AND R
r = 4 R sin A/2 sin B/2 sin […]
TRIANGLE TRIGONOMETRY
In any triangle the three sides a, b, c and the three angles A, B, C are called the elements of the triangle. In a triangle ABC, the side BC, opposite to angle A, is denoted by ‘a’. The side CA, opposite to angle B, is denoted by b and the side AB by […]
TRIGONOMETRIC EQUATIONS
What is a Trigonometric equation?
A trigonometric equation is an equation involving trigonometric functions of functions of unknown angles. The solution of a trigonometric equation is a value of the unknown angle that satisfies the equation. A trigonometric equation can have unlimited number of solutions, eg. If sin x=0, then x can have values […]
MAGNETIC FIELDS
DUE TO A STRAIGHT WIRE
As studied before the magnetic field due to a long current carrying wire is
B = ( m0i/4pd)(cosq1 - cosq2)
Now foe a long straight wire q1= 0 and q2= 180o, therefore the magnetic field is
B = m0i/2pd
SOLENOID
The magnetic field at any […]