Question

a. If 3 tan θ = 4, then the value of cos θ is :
(i) 3/4 (ii) 4/3 (iii) 3/5 (iv) 5/3
b. If cot θ = 12/5, then the value of sin θ is :
(i) 5/13 (ii) 12/13 (iii) 13/5 (iv) 13/12
c. If ▲ABC is right angled at C, then the value of sin(A + B) is:
(i) 0 (ii) 1 (iii) 1/2 (iv) not defined
d. In ▲ABC , right angled at B, AB = 24 cm, BC = 7 cm, the value of sin C is:
(i) 7/24 (ii) 25/7 (iii) 24/25 (iv) 25/24
e. If 15 cot A = 8, then the value of cos A . tan A is :
(i) 8/15 (ii) 15/17 (iii) 17/8 (iv) 8/17

Answer 1

Step-by-step explanation:

Given,

3tanθ=4

tanθ=

3

4

2cosθ+sinθ

4cosθ−sinθ

=

2cosθ+sinθ

4cosθ−sinθ

×

cosθ

cosθ

----------( Multiply and divide by cosθ )

=

cosθ

2cosθ+sinθ

cosθ

4cosθ−sinθ

=

2+

cosθ

sinθ

4−

cosθ

sinθ

=

2+tanθ

4−tanθ

=

2+

3

4

4−

3

4

=

6+4

12−4

=

10

8

=

5

4