1 of 2

EXERCISE 8.4

Q.2) Write all the other trigonometric ratios of ∠A in terms of sec A.

Solution:

sec2A = 1 + tan2A

tan2A

=

sec2A – 1

tan A

=

cos A =

1

sec A

tan A

=

sin A

cos A

sin A

=

tan A × cos A

1

sin A

=

×

sec A

∴

∴

∴

sin A

∴

=

sec A

∴

 

 

 

… (ii)

… (i)

[From (i) and (ii)]

… (iii)

2 of 2

EXERCISE 8.4

Q.2) Write all the other trigonometric ratios of ∠A in terms of sec A.

Solution:

1

sin A

cosec A

=

cosec A

=

1

cosec A

=

sec A

∴

∴

sec A

cot A

=

1

tan A

cot A

=

1

∴

sin A

=

sec A

 

 

 

 

tan A

=

 

÷

… (iii)

[From (iii)]

… [From (ii)]

… (ii)