Angles & Ratio

 

 

 

Contents

 

Ratio for Acute Angles

 

Ratio for General Angles

1  2

 

Ratio for Negative Angles

 

Ratio for Special Angles

 

Ratio for Complementary Angles

 

Other Trigonometry Ratios

  

Inverse Functions

 

Quiz 

 

 

Trigonometry Main Page

 

 

Remaining Trigonometric Ratios

The three remaining ratios are the reciprocal of the sine, cosine and tangent. They are

secant q = , cos q ¹ 0

cosecant q = ,sin q ¹ 0

cotangent q = tan q ¹ 0

These ratios are used in problems involving calculations where the questions are rather complex.

Example 1

Find the values of sec q, cosec q and cot q given that cos q = 4/5, q is acute.

sec q

sin q = 3/5
cosec q = 5/3
tan q = ¾
cot q = 4/3

Example 2

Given that A is obtuse and cot A = -2, find the exact value of 

a) sec A
b) cosec A

  1/tan A = -2

        tan A = - ½
basic angle = ½
            OP =
        sec A =
     cosec A =