Given that sin θ = $\Big(\dfrac{a}{b}\Big)$, then cos θ is equal to:

1. $\Big(\dfrac{b}{a}\Big)$

2. $\Big(\dfrac{a}{\sqrt{b^2 - a^2}}\Big)$

3. $\Big(\dfrac{b}{\sqrt{b^2 - a^2}}\Big)$

4. $\Big(\dfrac{\sqrt{b^2 - a^2}}{b}\Big)$

In the adjoining figure, D is the mid-point of BC. Then the value of $\Big(\dfrac{\cot y}{\cot x}\Big)$ is:

1. $\Big(\dfrac{1}{2}\Big)$

2. $\Big(\dfrac{1}{3}\Big)$

3. $\Big(\dfrac{1}{4}\Big)$

4. 2

If 3 cos θ = 1, then the value of cosec θ is:

1. $2\sqrt{2}$

2. $\Big(\dfrac{3}{2\sqrt{2}}\Big)$

3. $\Big(\dfrac{2\sqrt{3}}{3}\Big)$

4. $\Big(\dfrac{4}{3\sqrt{2}}\Big)$

If x cos A = 1 and tan A = y, then x² − y² is equal to:

1. 0

2. 1

3. −tan A

4. tan A