Question

if theta is in 3rd quadrant, 3tanA-4=0 then 5sin2A+3sinA+4cosA​

Answer 1

Answer:

3847

Step-by-step explanation:

384+38

2334-484=3847

Answer 2

Answer:

3tanA=4⇒tanA=

3

4

tan

2

A=

9

16

,sec

2

A=tan

2

+1=

9

16

+1=

9

25

secA=

3

−5

,cosA=

5

−3

[since A lies in the third quadrant]

sin

2

A=1−cos

2

A=1−

25

9

=

25

16

⇒sinA=

5

−4

so sinA=−

5

4

and cosA=−

5

3

⇒5×2sinAcosA+3sinA+4cosA

⇒5×2−

5

4

×

5

3

+3×

5

4

+4×

5

3

⇒10×

15

12

−

5

12

−

5

12

=0