If 5sinA-4=0 find the value of 3 tanA + 5 cosA.​

25/4

Step-by-step explanation:

5sinA-4=0

5sinA=4

sinA=4/5

sinA=opp/hyp

In triangle,

hypotenuse= 5 = c

opposite side = 4 = a

adjacent side = ? = b

Using Pythogoras Theorem,

a^2 + b^2 = c^2

4^2 + b^2 = 5^2

16 + b^2 = 25

b^2 = 25 - 16

b^2 = 9

b = 3

tanA = opp/adj = a/b = 3/4

cosA = adj/hyp = b/c = 4/5

3tanA + 5cosA

=> (3 x 3/4) + (5 x 4/5)

=> 9/4 + 4

=> 9/4 + 16/4  [L.C.M=4]

=>25/4

25/4 is the answer

Step-by-step explanation:

5sinA-4=0

=> 5sinA=4

=> sinA=4/5

=> sinA=opp/hyp

In triangle,

hypotenuse= c = 5

opposite side = a = 4  

adjacent side = b = ?  

Using Pythogoras Theorem,

a^2 + b^2 = c^2

=>4^2 + b^2 = 5^2

=>16 + b^2 = 25

=>b^2 = 25 - 16

=>b^2 = 9

=>b = 3

tanA = opp/adj = a/b = 3/4

cosA = adj/hyp = b/c = 4/5

3tanA + 5cosA

=> (3 x 3/4) + (5 x 4/5)

=> 9/4 + 4

=> 9/4 + 16/4  [L.C.M=4]

=>25/4