# If sin θ = 2 / 7 and tan θ > 0, what is the value of cos θ?

We will use the concept of trigonometry in order to find the value of cos θ.

## Answer: cos θ = 3√5 / 7

Let us see how we will use the concept of trigonometry in order to find the value of cos θ.

**Explanation:**

It is given that sin θ = 2 / 7 and tan θ > 0 hence, cos θ will also be positive.

Now, sin θ = 2 / 7

Squaring both sides, we get,

sin^{2} θ = 4 / 49

1 - cos^{2} θ = 4 / 49

cos^{2} θ = 1 - 4 / 49

cos^{2} θ = 45 / 49

cos θ = √45 / 7