Question

If cosx = 4/5, the value of tan x is _______.
1. 3/4
2. 4/3
3. 2/5
4. 2/3

Answer 1

Correct Answer - Option 1 : 3/4

Concept:

DIAGRAM

For a right-angled triangle shown above:

\(cos~θ =\frac{B}{H}\)

\(tan~θ =\frac{P}{B}\)

Calculation:

Given: cosx = 4/5

DIAGRAM

Applying Pythagoras theorem:

H² = B² + P²

P2 = H2 - B2

P2 = (5)2 - (4)2 = 9

P = 3

\(∴ tan~x=\frac{P}{B}=\frac{3}{4}\)