TRIGONOS METRY

Quadrant IQuadrant IIQuadrant III Quadrant IV

X-AXIS

Y-AXIS

Since the circumferenceof a circle is _______ ,one complete rotationwould have arc lengthof _______.

r

r

r

srad

2

r

r

r

srad

2

Positive Angle

Negative Angle Counterclockwise rotation.

Clockwise rotation.

Trigonometric Functions

& the relation between them

sin

cos

tan

opposite side

hypotenuse

adjacent side

hypotenuse

opposite side

adjacent side

1cot

tan

1sec

cos

1sec

sinco

sin , cosec + + - -cos , sec + - - +tan , cot + - + -

sin cos2

cos sin2

Remember sin( ) sin

The rest of the steps will be the same as followed previously all we have to take care is in which quadrant the resultant function lies in.

1sin( )

2area of LKM qr A B

1sin

2area of MKN pq B

1sin

2area of LKN pr A

area of LKM area of MKN

area of LKN

1 1

sin( ) sin2 2

1sin

2

qr A B pq B

pr A

sin( ) sin sinp p

A B A Bq r

sin( )

sin cos cos sin

A B

A B A B

sin( ) sin sinp p

A B A Bq r

sin[ ( )] sin cos( ) cos sin( )A B A B A B

sin( ) sin cos cos sinA B A B A B

sin sin cos cos sin2 2 2

A B A B A B

cos( ) cos cos sin sinA B A B A B

SOLUTION:

SOLUTION:

If in a ABC, cos3A + cos3B + cos3C = 3cosA cosB cosC, Prove that the triangle is equilateral.