Question

cosA=4/5 then value of tanA

Answer 1

Cos A=base/hypotenuse =4/5

Base=4,hypotenuse =5

By Pythagoras theorem,

Height =3

Tana=heigh /base=3/4

Answer 2

Given : Value of cos A = 4/5

To find : Value of tan A

Solution :

We can simply solve this mathematical problem by using the following mathematical process.

If we take the reference of a right angle triangle, then

• sin θ = Height/Hypotenuse
• cos θ = Base/Hypotenuse
• tan θ = Height/Base

Similarly,

cos A = 4/5

or,

Base/Hypotenuse = 4/5

Which implies,

In the associated right angle triangle :

• Base = 4
• Hypotenuse = 5

Now, we have to find the height, by using the Pythagoras theorem.

(Base)² + (Height)² = (Hypotenuse)²

(4)² + (Height)² = (5)²

(Height)² = 25-16

(Height)² = 9

Height = 3

So,

tan A = Height/Base = 3/4

Hence, value of tanA is 3/4